CVE-2025-32988 is a vulnerability identified in GnuTLS, a widely used open-source library implementing SSL/TLS protocols. The issue is a double-free vulnerability caused by incorrect ownership handling in the export logic of Subject Alternative Name (SAN) entries when they contain an otherName field. Specifically, if the type-id Object Identifier (OID) within the otherName is invalid or malformed, the function asn1_delete_structure() is erroneously called on an ASN.1 node that the caller does not own. This results in the same memory being freed twice, leading to undefined behavior such as memory corruption or program crashes. The vulnerability can be triggered remotely through public GnuTLS APIs without requiring authentication or user interaction, making it accessible to unauthenticated attackers. The flaw affects Red Hat Enterprise Linux 10 and potentially other systems using vulnerable GnuTLS versions. The severity is rated medium with a CVSS score of 6.5, reflecting the network attack vector, high attack complexity, no privileges required, no user interaction, and impact limited to integrity loss and availability disruption. While no known exploits are currently reported, the vulnerability poses a risk of denial of service or memory corruption, which could be leveraged for further exploitation depending on allocator behavior and system context. The vulnerability was published on July 10, 2025, with no patches linked yet, indicating the need for vigilance and prompt remediation once fixes are available.

For European organizations, this vulnerability poses a risk primarily of denial of service and potential memory corruption in systems using GnuTLS, especially those running Red Hat Enterprise Linux 10. Services relying on TLS for secure communications, such as web servers, mail servers, VPN gateways, and other network appliances, may be disrupted if exploited. This could lead to temporary service outages, impacting business continuity and customer trust. Memory corruption could theoretically be leveraged for further attacks, although the complexity and conditions reduce this likelihood. Organizations in sectors with high reliance on secure communications, such as finance, healthcare, and government, may face increased operational risks. The vulnerability's remote exploitability without authentication increases the attack surface, making exposed internet-facing services particularly vulnerable. Given the widespread use of GnuTLS in open-source software stacks, the scope of affected systems across Europe is significant, necessitating proactive mitigation to prevent exploitation.

Organizations should monitor vendor advisories closely and apply patches or updates to GnuTLS and Red Hat Enterprise Linux 10 as soon as they become available. In the interim, consider implementing network-level protections such as Web Application Firewalls (WAFs) or Intrusion Prevention Systems (IPS) to detect and block malformed TLS handshake attempts that could trigger the vulnerability. Conduct thorough inventory and auditing of systems using GnuTLS to identify exposed services. Employ strict input validation and anomaly detection on TLS traffic where possible. Limit exposure of vulnerable services to untrusted networks by using network segmentation and access controls. Regularly update and harden TLS configurations to reduce attack vectors. Additionally, organizations should prepare incident response plans to quickly address potential denial of service events stemming from exploitation attempts. Collaboration with upstream open-source communities and vendors can facilitate timely patch deployment and vulnerability management.