bleepingcomputer.com
By Lawrence Abrams
December 6, 2025

Over 77,000 Internet-exposed IP addresses are vulnerable to the critical React2Shell remote code execution flaw (CVE-2025-55182), with researchers now confirming that attackers have already compromised over 30 organizations across multiple sectors.

React2Shell is an unauthenticated remote code execution vulnerability that can be exploited via a single HTTP request and affects all frameworks that implement React Server Components, including Next.js, which uses the same deserialization logic.

React disclosed the vulnerability on December 3, explaining that unsafe deserialization of client-controlled data inside React Server Components enables attackers to trigger remote, unauthenticated execution of arbitrary commands.

Developers are required to update React to the latest version, rebuild their applications, and then redeploy to fix the vulnerability.

On December 4, security researcher Maple3142 published a working proof-of-concept demonstrating remote command execution against unpatched servers. Soon after, scanning for the flaw accelerated as attackers and researchers began using the public exploit with automated tools.

Over 77,000 vulnerable IP addresses
Shadowserver Internet watchdog group now reports that it has detected 77,664 IP addresses vulnerable to the React2Shell flaw, with approximately 23,700 in the United States.

The researchers determined that IP addresses were vulnerable using a detection technique developed by Searchlight Cyber/Assetnote, where an HTTP request was sent to servers to exploit the flaw, and a specific response was checked to confirm whether a device was vulnerable.

GreyNoise also recorded 181 distinct IP addresses attempting to exploit the flaw over the past 24 hours, with most of the traffic appearing automated. The researchers say the scans are primarily originating from the Netherlands, China, the United States, Hong Kong, and a small number of other countries.

Palo Alto Networks reports that more than 30 organizations have already been compromised through the React2Shell flaw, with attackers exploiting the vulnerability to run commands, conduct reconnaissance, and attempt to steal AWS configuration and credential files.

These compromises include intrusions linked to known state-associated Chinese threat actors.

Widespread exploitation of React2Shell
Since its disclosure, researchers and threat intelligence companies have observed widespread exploitation of the CVE-2025-55182 flaw.

GreyNoise reports that attackers frequently begin with PowerShell commands that perform a basic math function to confirm the device is vulnerable to the remote code execution flaw.

These tests return predictable results while leaving minimal signs of exploitation:

powershell -c "4013841979"
powershell -c "4032043488"
Once remote code execution was confirmed, attackers were seen executing base64-encoded PowerShell commands that download additional scripts directly into memory.

powershell -enc <base64>
One observed command executes a second-stage PowerShell script from the external site (23[.]235[.]188[.]3), which is used to disable AMSI to bypass endpoint security and deploy additional payloads.

According to VirusTotal, the PowerShell script observed by GreyNoise installs a Cobalt Strike beacon on the targeted device, giving threat actors a foothold on the network.

Amazon AWS threat intelligence teams also saw rapid exploitation hours after the disclosure of the React CVE-2025-55182 flaw, with infrastructure associated with China-linked APT hacking groups known as Earth Lamia and Jackpot Panda.

In this exploitation, the threat actors perform reconnaissance on vulnerable servers by using commands such as whoami and id, attempting to write files, and reading /etc/passwd.

Palo Alto Networks also observed similar exploitation, attributing some of it to UNC5174, a Chinese state-sponsored threat actor believed to be tied to the Chinese Ministry of State Security.

"Unit 42 observed threat activity we assess with high confidence is consistent with CL-STA-1015 (aka UNC5174), a group suspected to be an initial access broker with ties to the Chinese Ministry of State Security," Justin Moore, Senior Manager at Palo Alto Networks Unit 42, told BleepingComputer via email.

"In this activity, we observed the deployment of Snowlight and Vshell malware, both highly consistent with Unit 42 knowledge of CL-STA-1015 (also known as UNC5174)."

The deployed malware in these attacks is:

Snowlight: A malware dropper that allows remote attackers to drop additional payloads on breached devices.
Vshell: A backdoor commonly used by Chinese hacking groups for remote access, post-exploitation activity, and to move laterally through a compromised network.
The rush to patch
Due to the severity of the React flaw, companies worldwide have rushed to install the patch and apply mitigations.

Yesterday, Cloudflare rolled out emergency detections and mitigations for the React flaw in its Web Application Firewall (WAF) due to its widespread exploitation and severity.

However, the update inadvertently caused an outage affecting numerous websites before the rules were corrected.

CISA has also added CVE-2025-55182 to the Known Exploited Vulnerabilities (KEV) catalog, requiring federal agencies to apply patches by December 26, 2025, under Binding Operational Directive 22-01.

Organizations using React Server Components or frameworks built on top of them are advised to apply updates immediately, rebuild and redeploy their applications, and review logs for signs of PowerShell or shell command execution.

bleepingcomputer.com
By Sergiu Gatlan
November 7, 2025

Cisco warned this week that two vulnerabilities, which have been used in zero-day attacks, are now being exploited to force ASA and FTD firewalls into reboot loops.

The tech giant released security updates on September 25 to address the two security flaws, stating that CVE-2025-20362 enables remote threat actors to access restricted URL endpoints without authentication, while CVE-2025-20333 allows authenticated attackers to gain remote code execution on vulnerable devices.

When chained, these vulnerabilities allow remote, unauthenticated attackers to gain complete control over unpatched systems.

The same day, CISA issued an emergency directive ordering U.S. federal agencies to secure their Cisco firewall devices against attacks using this exploit chain within 24 hours. CISA also mandated them to disconnect ASA devices reaching their end of support (EoS) from federal organization networks.

Threat monitoring service Shadowserver is currently tracking over 34,000 internet-exposed ASA and FTD instances vulnerable to CVE-2025-20333 and CVE-2025-20362 attacks, down from the nearly 50,000 unpatched firewalls it spotted in September.

Now exploited in DoS attacks
"Cisco previously disclosed new vulnerabilities in certain Cisco ASA 5500-X devices running Cisco Secure Firewall ASA software with VPN web services enabled, discovered in collaboration with several government agencies. We attributed these attacks to the same state-sponsored group behind the 2024 ArcaneDoor campaign and urged customers to apply the available software fixes," a Cisco spokesperson told BleepingComputer this week.

"On November 5, 2025, Cisco became aware of a new attack variant targeting devices running Cisco Secure ASA Software or Cisco Secure FTD Software releases affected by the same vulnerabilities. This attack can cause unpatched devices to unexpectedly reload, leading to denial of service (DoS) conditions."

CISA and Cisco linked the attacks to the ArcaneDoor campaign, which exploited two other Cisco firewall zero-day bugs (CVE-2024-20353 and CVE-2024-20359) to breach government networks worldwide starting in November 2023. The UAT4356 threat group (tracked as STORM-1849 by Microsoft) behind the ArcaneDoor attacks deployed previously unknown Line Dancer in-memory shellcode loader and Line Runner backdoor malware to maintain persistence on compromised systems.

On September 25, Cisco fixed a third critical vulnerability (CVE-2025-20363) in its Cisco IOS and firewall software, which can allow unauthenticated threat actors to execute arbitrary code remotely. However, it didn't directly link it to the attacks exploiting CVE-2025-20362 and CVE-2025-20333, saying that its Product Security Incident Response Team was "not aware of any public announcements or malicious use of the vulnerability."

Since then, attackers have started exploiting another recently patched RCE vulnerability (CVE-2025-20352) in Cisco networking devices to deploy rootkit malware on unprotected Linux boxes.

More recently, on Thursday, Cisco released security updates to patch critical security flaws in its Contact Center software, which could enable attackers to bypass authentication (CVE-2025-20358) and execute commands with root privileges (CVE-2025-20354).

"We strongly recommend all customers upgrade to the software fixes outlined in our security advisories," Cisco added on Thursday.

CISA says a maximum severity vulnerability in AMI's MegaRAC Baseboard Management Controller (BMC) software, which enables attackers to hijack and brick servers, is currently under active exploitation.
CISA has confirmed that a maximum severity vulnerability in AMI's MegaRAC Baseboard Management Controller (BMC) software is now actively exploited in attacks.

The MegaRAC BMC firmware provides remote system management capabilities for troubleshooting servers without being physically present, and it's used by several vendors (including HPE, Asus, and ASRock) that supply equipment to cloud service providers and data centers.

This authentication bypass security flaw (tracked as CVE-2024-54085) can be exploited by remote unauthenticated attackers in low-complexity attacks that don't require user interaction to hijack and potentially brick unpatched servers.

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.

Hackers are actively exploiting CVE-2025-49113, a critical vulnerability in the widely used Roundcube open-source webmail application that allows remote execution.
The security issue has been present in Roundcube for over a decade and impacts versions of Roundcube webmail 1.1.0 through 1.6.10. It received a patch on June 1st.

It took attackers just a couple of days to reverse engineer the fix, weaponize the vulnerability, and start selling a working exploit on at least one hacker forum.

Roundcube is one of the most popular webmail solutions as the product is included in offers from well-known hosting providers such as GoDaddy, Hostinger, Dreamhost, or OVH.
"Email armageddon"

CVE-2025-49113 is a post-authentication remote code execution (RCE) vulnerability that received a critical severity score of 9.9 out of 10 and is described as “email armageddon.”

It was discovered and reported by Kirill Firsov, the CEO of the cybersecurity company FearsOff, who decided to publish the technical details before the end of the responsible disclosure period because an exploit had become available.

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.

Fortinet has disclosed a second authentication bypass vulnerability that was fixed as part of a January 2025 update for FortiOS and FortiProxy devices.

​Apple has released security updates to fix this year's first zero-day vulnerability, tagged as actively exploited in attacks targeting iPhone users.

Threat actors have been exploiting a vulnerability in the Roundcube Webmail client to target government organizations in the Commonwealth of Independent States (CIS) region, the successor of the former Soviet Union.

The Cardinal cybercrime group (Storm-1811, UNC4394), who are the main operators of the Black Basta ransomware, is suspected of exploiting a Windows privilege escalation vulnerability, CVE-2024-26169, before a fix was made available.

Hackers have started to target a critical severity vulnerability in the WP Automatic plugin for WordPress to create user accounts with administrative privileges and to plant backdoors for long-term access.

Security researchers have released a proof-of-concept (PoC) exploit for a critical vulnerability in Fortinet's FortiClient Enterprise Management Server (EMS) software, which is now actively exploited in attacks.

Hackers are attempting to leverage a recently fixed critical vulnerability (CVE-2023-50164) in Apache Struts that leads to remote code execution, in attacks that rely on publicly available proof-of-concept exploit code.

Sophos was forced to backport a security update for CVE-2022-3236 for end-of-life (EOL) firewall firmware versions after discovering hackers actively exploiting the flaw in attacks.

Qualcomm is warning of three zero-day vulnerabilities in its GPU and Compute DSP drivers that hackers are actively exploiting in attacks.

US-based IT software company Ivanti warned customers today that a critical Sentry API authentication bypass vulnerability is being exploited in the wild.