CVE-2024-28835 is a vulnerability identified in GnuTLS version 3.8.3, a widely used open-source library that provides cryptographic functionality and TLS/SSL protocols. The flaw arises when the "certtool --verify-chain" command attempts to verify a specially crafted .pem certificate bundle. Specifically, the vulnerability leads to an uncaught exception causing the application to crash. This crash is triggered by malformed input that the verification process cannot handle gracefully, resulting in a denial of service (DoS) condition. The vulnerability does not impact confidentiality or integrity directly but affects availability by causing the certtool utility to terminate unexpectedly. The CVSS 3.1 base score is 5.0 (medium severity), reflecting that the attack vector is local (AV:L), requires low complexity (AC:L), privileges (PR:L), and user interaction (UI:R). The scope remains unchanged (S:U), and there is no impact on confidentiality or integrity, only availability (A:H). No known exploits are currently reported in the wild, and no patches or vendor advisories are linked yet. Given that certtool is often used for certificate management and validation in security-sensitive environments, this vulnerability could disrupt automated certificate verification workflows or administrative tasks relying on GnuTLS tools.

For European organizations, the primary impact of CVE-2024-28835 is a potential denial of service in systems or processes that utilize GnuTLS certtool for certificate chain verification. This could affect IT infrastructure teams managing PKI certificates, automated certificate renewal systems, or security auditing tools that rely on GnuTLS. While the vulnerability does not allow data leakage or unauthorized access, the disruption of certificate verification could delay critical security operations, potentially leading to expired or unverified certificates in production environments. This may indirectly increase the risk of man-in-the-middle attacks or service outages if certificate validation is bypassed or delayed. Organizations with automated DevOps pipelines or security monitoring that incorporate GnuTLS certtool are particularly at risk. The medium severity score indicates moderate risk, but the need for local privileges and user interaction limits remote exploitation, reducing the threat surface. However, insider threats or compromised local accounts could exploit this vulnerability to disrupt operations.

To mitigate CVE-2024-28835, European organizations should first identify all systems running GnuTLS version 3.8.3, especially those using the certtool utility for certificate verification. Until a patch is released, organizations should avoid processing untrusted or unauthenticated .pem bundles with certtool to prevent crashes. Implement strict input validation and restrict access to certtool commands to trusted administrators only. Monitoring and alerting on certtool crashes can help detect exploitation attempts. Where possible, isolate certificate verification processes in sandboxed or containerized environments to limit impact. Organizations should also track vendor advisories and apply patches promptly once available. As a longer-term measure, consider integrating alternative certificate verification tools or libraries with more robust input handling. Additionally, review and harden local user privilege assignments to reduce the risk of exploitation by unauthorized users.