WGSA-2023-00001

OpenSSH Server 9.1 Double Free Vulnerability (CVE-2023-25136)

Medium Published 2023-03-22Updated 2026-07-27

Summary #

On February 3, 2023, researchers at Qualys disclosed CVE-2023-25136, a double free vulnerability in OpenSSH Server v9.1. The exploit is non-trivial but a successful exploit could allow an unauthenticated attacker to execute arbitrary code on an unprotected system.

CVE identifiers #

CVE IDDescriptionCVSS
CVE-2023-25136 OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during options.kex_algorithms handling. This is fixed in OpenSSH 9.2. The double free can be leveraged, by an unauthenticated remote attacker in the default configuration, to jump to any location in the sshd address space. One third-party report states "remote code execution is theoretically possible."

Product status #

ProductAffectedNot affected
DimensionAll versions
Fireware OSAll versions
Secure Wi-FiAll versions

Solution #

No solution has been published for this advisory.

References #