CVE-2025-32990 is a heap-based buffer overflow vulnerability identified in the GnuTLS library, specifically within the certtool utility's template parsing logic on Red Hat Enterprise Linux 10. The flaw arises due to an off-by-one error when certtool reads certain settings from a template file, which leads to an out-of-bounds NULL pointer write. This memory corruption can cause the certtool utility, and potentially the entire system, to crash, resulting in a denial-of-service (DoS) condition. The vulnerability does not require authentication or user interaction to be exploited, and it can be triggered remotely if an attacker can supply a crafted template file to the certtool utility. However, the impact is limited to integrity and availability, as there is no indication of confidentiality compromise. The CVSS v3.1 score of 6.5 (medium severity) reflects the network attack vector, low attack complexity, no privileges required, no user interaction, unchanged scope, no confidentiality impact, low integrity impact, and low availability impact. There are no known exploits in the wild at the time of publication, and no patches have been linked yet. The vulnerability affects Red Hat Enterprise Linux 10 installations that use the vulnerable version of GnuTLS and the certtool utility, which is commonly employed for certificate management tasks in enterprise environments.

For European organizations, this vulnerability poses a risk primarily in environments where Red Hat Enterprise Linux 10 is deployed and where the certtool utility is used for certificate management. The denial-of-service caused by memory corruption could disrupt critical services relying on TLS certificates, such as web servers, VPN gateways, and internal PKI infrastructures. This disruption could lead to temporary loss of availability of secure communications, impacting business operations and potentially causing compliance issues with regulations such as GDPR if secure data transmissions are interrupted. While the vulnerability does not directly expose sensitive data, the resulting service outages could indirectly affect confidentiality and integrity by forcing fallback to less secure configurations or manual certificate handling. The medium severity rating suggests that while the threat is non-trivial, it is not immediately critical, but organizations should prioritize remediation to avoid potential exploitation, especially in high-availability or security-sensitive environments.

European organizations should implement the following specific mitigation steps: 1) Monitor Red Hat and GnuTLS advisories closely for the release of patches addressing CVE-2025-32990 and apply them promptly once available. 2) Restrict access to systems running Red Hat Enterprise Linux 10 and limit who can execute or supply input to the certtool utility, minimizing exposure to crafted template files. 3) Employ input validation and sanitization controls on any automated processes that generate or handle certtool templates to prevent malicious template injection. 4) Implement runtime protections such as memory corruption mitigations (e.g., Address Space Layout Randomization (ASLR), stack canaries) and enable security modules like SELinux to limit the impact of potential exploitation. 5) Conduct regular audits of certificate management workflows to detect unusual crashes or behavior in certtool usage. 6) Prepare incident response plans to quickly recover from potential DoS events caused by this vulnerability. These measures go beyond generic patching by focusing on reducing attack surface and improving detection and response capabilities.