CVE-2025-5915 is a heap-based buffer overflow vulnerability discovered in the libarchive library, which is widely used for handling archive files in various Linux distributions, including Red Hat Enterprise Linux 10. The vulnerability occurs when the size of a filter block processed by libarchive exceeds the Lempel-Ziv-Storer-Schieber (LZSS) window size. This causes the library to perform a heap buffer over-read, reading memory beyond the allocated buffer. Such out-of-bounds reads can lead to unpredictable program behavior, including crashes resulting in denial of service, or potentially the disclosure of sensitive information stored in adjacent memory regions. The vulnerability requires local access with low privileges and user interaction to trigger, as indicated by the CVSS vector (AV:L/AC:L/PR:L/UI:R). No authentication is required, and the scope is unchanged (S:U). The CVSS score of 6.6 reflects a medium severity level, balancing the potential confidentiality impact with the exploitation complexity. Currently, there are no known exploits in the wild, but the vulnerability poses a risk to systems that process untrusted archive files using libarchive. Red Hat Enterprise Linux 10 is specifically affected, and organizations relying on this OS for critical workloads should prioritize remediation once patches are released. The vulnerability highlights the risks associated with parsing complex archive formats and the importance of robust input validation and memory management in security-critical libraries.

For European organizations, the impact of CVE-2025-5915 can be significant in environments where Red Hat Enterprise Linux 10 is deployed, especially in sectors processing large volumes of archive files such as finance, government, telecommunications, and critical infrastructure. Successful exploitation could lead to denial of service conditions, disrupting business operations and availability of critical services. Additionally, the potential disclosure of sensitive information from memory could expose confidential data, leading to compliance violations under GDPR and other data protection regulations. The requirement for local access and user interaction limits remote exploitation risks but does not eliminate insider threats or risks from compromised user accounts. Organizations running automated archive processing or file ingestion systems may be particularly vulnerable if untrusted archives are handled without sufficient validation. The medium severity rating suggests that while the vulnerability is not trivially exploitable remotely, the consequences of exploitation warrant timely mitigation to avoid operational and reputational damage.

1. Apply official patches from Red Hat as soon as they become available to address the vulnerability in libarchive. 2. Until patches are deployed, restrict processing of untrusted or unauthenticated archive files, especially from external sources. 3. Implement strict input validation and sandboxing for applications that handle archive extraction to limit the impact of potential exploitation. 4. Monitor system logs and application behavior for crashes or anomalies indicative of exploitation attempts. 5. Employ the principle of least privilege to limit user permissions, reducing the risk posed by local attackers. 6. Educate users about the risks of interacting with untrusted archive files and enforce policies to minimize user interaction with suspicious content. 7. Consider deploying runtime memory protection mechanisms such as Address Space Layout Randomization (ASLR) and heap protection features to mitigate exploitation impact. 8. Conduct regular security assessments and penetration testing focused on archive processing components to identify residual risks.