The maintainers of OpenSSH have released a new version, 9.2, to fix a number of security issues, including a memory safety vulnerability in the OpenSSH server. This vulnerability, tracked as CVE-2023-25136, is a pre-authentication double free vulnerability that was introduced in version 9.1. It is not believed to be exploitable, as it occurs in the unprivileged pre-auth process that is subject to chroot(2) and is further sandboxed on most major platforms. The security researcher Mantas Mikulenas reported the flaw to OpenSSH in July 2022. OpenSSH is an open source implementation of the secure shell protocol that provides encrypted communications over an unsecured network in a client-server architecture. The vulnerability is a double free in the options.kex algorithms, according to Qualys researcher Saeed Abbasi. This double free in the unprivileged sshd process can lead to memory corruption, which can cause a crash or allow an attacker to execute arbitrary code. Exploiting this issue is difficult due to the protective measures put in place by modern memory allocators and the privilege separation and sandboxing implemented in the impacted sshd process. To protect against potential security threats, users are advised to update to OpenSSH 9.2.
This Cyber News was published on thehackernews.com. Publication date: Mon, 06 Feb 2023 10:03:03 +0000