A critical vulnerability in ModSecurity’s Apache module has been disclosed, potentially exposing millions of web servers worldwide to denial-of-service attacks.
The flaw, tracked as CVE-2025-47947 and assigned a CVSS score of 7.5, affects the popular open-source web application firewall’s handling of JSON payloads under specific conditions.
Security researchers have confirmed that attackers can exploit this vulnerability with minimal effort, requiring only a single crafted request to consume excessive server memory and potentially crash targeted systems.
ModSecurity DoS Flaw (CVE-2025-47947)
The vulnerability was initially reported in March 2025 by Simon Studer from Netnea on behalf of Swiss Post, though it took several months for developers to successfully reproduce and understand the root cause.
CVE-2025-47947 specifically affects mod_security2, the Apache module version of ModSecurity, while the newer libmodsecurity3 implementation remains unaffected.
The flaw emerges when two specific conditions are met simultaneously: the incoming payload must have a Content-Type of application/json, and there must be at least one active rule utilizing the sanitiseMatchedBytes action.
Palo Alto Networks has disclosed a high-severity vulnerability impacting PAN-OS software that could cause a denial-of-service (DoS) condition on susceptible devices.
The flaw, tracked as CVE-2024-3393 (CVSS score: 8.7), impacts PAN-OS versions 10.X and 11.X, as well as Prisma Access running PAN-OS versions. It has been addressed in PAN-OS 10.1.14-h8, PAN-OS 10.2.10-h12, PAN-OS 11.1.5, PAN-OS 11.2.3, and all later PAN-OS versions.
In this research, we uncovered several vulnerabilities and security flaws within the Prometheus ecosystem. These findings span across three major areas: information disclosure, denial-of-service (DoS), and code execution. We found that exposed Prometheus servers or exporters, often lacking proper authentication, allowed attackers to easily gather sensitive information, such as credentials and API keys.
Additionally, we identified an alarming risk of DoS attacks stemming from the exposure of pprof debugging endpoints, which, when exploited, could overwhelm and crash Prometheus servers, Kubernetes pods and other hosts.
A case study on advanced fuzzing techniques for network services.
The Internet Systems Consortium (ISC) released BIND security updates that fixed remotely exploitable DoS bugs in the DNS software suite.
Cisco has fixed a critical severity vulnerability that lets attackers add new users with root privileges and permanently crash Security Email Gateway (SEG) appliances using emails with malicious attachments.
Tracked as CVE-2024-20401, this arbitrary file write security flaw in the SEG content scanning and message filtering features is caused by an absolute path traversal weakness that allows replacing any file on the underlying operating system.
Newly discovered HTTP/2 protocol vulnerabilities called
Deep technical analysis of the CONTINUATION Flood: a class of vulnerabilities within numerous HTTP/2 protocol implementations. In many cases, it poses a more severe threat compared to the Rapid Reset: a single machine (and in certain instances, a mere single TCP connection or a handful of frames) has the potential to disrupt server availability, with consequences ranging from server crashes to substantial performance degradation. Remarkably, requests that constitute an attack are not visible in HTTP access logs. **A simplified security advisory and the list of affected projects can be found in: http2-continuation-flood
IT security software company Ivanti has released patches to fix multiple security vulnerabilities impacting its Connect Secure and Policy Secure gateways.
A new Denial-of-Service (DoS) attack targets application-layer protocols that draw on the User Datagram Protocol (UDP) for end-to-end communication. The vulnerability affects both legacy and contemporary protocols. Discovered by Christian Rossow and Yepeng Pan, the attack puts an estimated 300,000 Internet hosts and their networks at risk.
Majority of public-facing devices still unpatched against critical vulns from as far back as 2022
A new Python project called 'Wall of Flippers' detects Bluetooth spam attacks launched by Flipper Zero and Android devices.
Microsoft says the early June disruptions to its Microsoft’s flagship office suite — including the Outlook email apps — were denial-of-service attacks by a shadowy new hacktivist group. In a blog post published Friday evening after The Associated Press sought clarification on the sporadic but serious outages, Microsoft confirmed that that they were DDoS attacks by a group calling itself Anonymous Sudan, which some security researchers believe is Russia-affiliated. The software giant offered few details on the attack. It did not comment on how many customers were affected.
Researchers from Bitsight and Curesec have jointly discovered a high-severity vulnerability — tracked as CVE-2023-29552 — in the Service Location Protocol (SLP)
We’ve seen spam campaigns in the open-source ecosystems in the past year, but this month was by far the worst one we’ve seen yet. Apparently, attackers found the unvetted open-source ecosystems as an…
Cisco has disclosed today a high-severity zero-day vulnerability affecting the latest generation of its IP phones and exposing them to remote code execution and denial of service (DoS) attacks.
La bibliothèque de chiffrement web open source OpenSSL est affectée par une vulnérabilité pouvant servir à des attaques par déni de service. Les versions 1.0.2, 1.1.1 et 3.0 doivent être mises à jour dès que possible.
