CVE-2025-5351 is a medium-severity vulnerability identified in the key export functionality of libssh as used in Red Hat Enterprise Linux 10. The flaw arises within an internal function responsible for converting cryptographic keys into serialized formats. Specifically, during error handling, a memory structure is freed but not cleared properly. If an additional failure occurs later in the function, this can lead to a double free condition. Double free vulnerabilities occur when the same memory is deallocated more than once, which can corrupt the heap memory. In this case, heap corruption or application instability may result, particularly in low-memory scenarios where key export operations are performed. The vulnerability requires network access (AV:N), has a high attack complexity (AC:H), requires low privileges (PR:L), and does not require user interaction (UI:N). The impact on confidentiality and integrity is low, and availability is not affected. No known exploits are currently reported in the wild. The vulnerability is specific to Red Hat Enterprise Linux 10, indicating it affects systems running this OS version with libssh's key export functionality. The flaw could cause instability or crashes in applications relying on key export, potentially disrupting cryptographic operations or services that depend on them. However, it does not directly allow code execution or privilege escalation. The vulnerability's medium severity reflects the limited impact and exploitation complexity.

For European organizations, the primary impact of CVE-2025-5351 lies in potential system instability or application crashes during cryptographic key export operations on Red Hat Enterprise Linux 10 systems. Organizations that rely heavily on cryptographic services, secure communications, or automated key management processes could experience disruptions or degraded service reliability. While the vulnerability does not directly compromise confidentiality or allow remote code execution, heap corruption could be leveraged in complex attack chains or cause denial-of-service conditions. This may affect critical infrastructure, financial institutions, or government agencies using Red Hat Enterprise Linux 10 in their server environments. The medium severity and lack of known exploits reduce immediate risk, but the vulnerability could be exploited in targeted attacks or combined with other vulnerabilities. Organizations with strict uptime and reliability requirements should be particularly cautious. Additionally, since the flaw requires low privileges but high attack complexity, insider threats or attackers with limited access could attempt exploitation, emphasizing the need for robust internal security controls.

To mitigate CVE-2025-5351 effectively, European organizations should: 1) Apply patches or updates from Red Hat as soon as they become available, ensuring libssh and related components are updated to versions that fix the double free issue. 2) Monitor system logs and application behavior for signs of heap corruption or instability related to key export operations, especially under low-memory conditions. 3) Restrict access to systems running Red Hat Enterprise Linux 10 to trusted users and networks to reduce the risk of exploitation, given the vulnerability requires network access but low privileges. 4) Implement memory protection mechanisms such as Address Space Layout Randomization (ASLR) and heap protection features available in the OS to mitigate exploitation impact. 5) Conduct regular security audits and vulnerability scans focusing on cryptographic libraries and key management processes. 6) Consider isolating critical cryptographic operations in hardened environments or containers to limit the blast radius of potential crashes or instability. 7) Educate system administrators about the vulnerability and encourage prompt incident response readiness in case exploitation attempts are detected.