libssh Double Free Vulnerability in Key Export Functionality

A double free vulnerability has been identified in libssh's key export functionality, specifically in versions 0.10.0 and later when built with OpenSSL 3.0 or later. The issue arises in the pki_key_to_blob() function, where a memory structure is freed during error handling but not properly cleared. This oversight can lead to a double free situation if another error occurs later in the function, potentially causing heap corruption or application crashes, particularly in low-memory conditions.

Impact

Exploitation of this vulnerability could lead to heap corruption or instability of applications using libssh for exporting SSH key material, especially in low-memory environments.