CVE-2025-5351 Libssh: double free vulnerability in libssh key export functions

Description

A flaw was found in the key export functionality of libssh. The issue occurs in the internal function responsible for converting cryptographic keys into serialized formats. During error handling, a memory structure is freed but not cleared, leading to a potential double free issue if an additional failure occurs later in the function. This condition may result in heap corruption or application instability in low-memory scenarios, posing a risk to system reliability where key export operations are performed.

Exploitable remotely over the network, with an ordinary account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Affected products and versions