CVE-2024-6387 Information

Description

A signal handler race condition was found in OpenSSH’s server (sshd) 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().

Reference

https://access.redhat.com/security/cve/CVE-2024-6387 https://bugzilla.redhat.com/show_bug.cgi?id=2294604 https://www.qualys.com/2024/07/01/cve-2024-6387/regresshion.txt http://www.openwall.com/lists/oss-security/2024/07/01/12 https://github.com/zgzhang/cve-2024-6387-poc https://ubuntu.com/security/CVE-2024-6387 https://ubuntu.com/security/notices/USN-6859-1 https://www.suse.com/security/cve/CVE-2024-6387.html https://explore.alas.aws.amazon.com/CVE-2024-6387.html https://archlinux.org/news/the-sshd-service-needs-to-be-restarted-after-upgrading-to-openssh-98p1/ https://www.openssh.com/txt/release-9.8 https://lists.mindrot.org/pipermail/openssh-unix-announce/2024-July/000158.html https://lists.mindrot.org/pipermail/openssh-unix-dev/2024-July/041431.html https://blog.qualys.com/vulnerabilities-threat-research/2024/07/01/regresshion-remote-unauthenticated-code-execution-vulnerability-in-openssh-server https://www.theregister.com/2024/07/01/regresshion_openssh/ https://news.ycombinator.com/item?id=40843778 https://security-tracker.debian.org/tracker/CVE-2024-6387 https://github.com/oracle/oracle-linux/issues/149 https://github.com/rapier1/hpn-ssh/issues/87 https://stackdiary.com/openssh-race-condition-in-sshd-allows-remote-code-execution/ https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2024-0010 http://www.openwall.com/lists/oss-security/2024/07/01/13 https://security.netapp.com/advisory/ntap-20240701-0001/