CVE-2024-6409

CVE Details

Release Date:

2024-07-08

Description

A signal handler race condition vulnerability was found in OpenSSH's server (sshd) in Red Hat Enterprise Linux 9, where a client does not authenticate within LoginGraceTime seconds (120 by default, 600 in old OpenSSH versions), then sshd's SIGALRM handler is called asynchronously. However, this signal handler calls various functions that are not async-signal-safe, for example, syslog(). This issue leaves it vulnerable to a signal handler race condition on the cleanup_exit() function, which introduces the same vulnerability as CVE-2024-6387 in the unprivileged child of the SSHD server. As a consequence of a successful attack, in the worst case scenario, the attacker may be able to perform a remote code execution (RCE) within unprivileged user running the sshd server. This vulnerability affects only the sshd server shipped with Red Hat Enterprise Linux 9, while upstream versions of sshd are not impact by this flaw.

See more information about CVE-2024-6409 from MITRE CVE dictionary and NIST NVD

CVSS Scoring

NOTE: The following CVSS v3.1 metrics and score provided are preliminary and subject to review.

Base Score:	7	CVSS Vector:	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H
Attack Vector:	Network	Attack Complexity:	High
Privileges Required:	None	User Interaction:	None
Scope:	Unchanged	Confidentiality Impact:	Low
Integrity Impact:	Low	Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 9 (openssh)	ELSA-2024-4457	2024-07-10

This page is generated automatically and has not been checked for errors or omissions. For clarification or corrections please contact the Oracle Linux ULN team