CVE-2024-6387
Openssh: regresshion - race condition in ssh allows rce/dos
CVSS Score
8.1
EPSS Score
0.0%
EPSS Percentile
0th
A security regression (CVE-2006-5051) was discovered in OpenSSH's server (sshd). There is a race condition which can lead sshd to handle some signals in an unsafe manner. An unauthenticated, remote attacker may be able to trigger it by failing to authenticate within a set time period.
| CWE | CWE-364 |
| Published | Jul 1, 2024 |
| Last Updated | Dec 11, 2025 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
Red Hat / Red Hat Enterprise Linux 9
All versions affected Red Hat / Red Hat Enterprise Linux 9
All versions affected Red Hat / Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions
All versions affected Red Hat / Red Hat Enterprise Linux 9.2 Extended Update Support
All versions affected Red Hat / Red Hat OpenShift Container Platform 4.13
All versions affected Red Hat / Red Hat OpenShift Container Platform 4.14
All versions affected Red Hat / Red Hat OpenShift Container Platform 4.15
All versions affected Red Hat / Red Hat OpenShift Container Platform 4.16
All versions affected Red Hat / Red Hat Ceph Storage 5
All versions affected Red Hat / Red Hat Ceph Storage 6
All versions affected Red Hat / Red Hat Ceph Storage 7
All versions affected Red Hat / Red Hat Enterprise Linux 10
All versions affected Red Hat / Red Hat Enterprise Linux 6
All versions affected Red Hat / Red Hat Enterprise Linux 7
All versions affected Red Hat / Red Hat Enterprise Linux 8
All versions affected References
access.redhat.com: https://access.redhat.com/errata/RHSA-2024:4312 access.redhat.com: https://access.redhat.com/errata/RHSA-2024:4340 access.redhat.com: https://access.redhat.com/errata/RHSA-2024:4389 access.redhat.com: https://access.redhat.com/errata/RHSA-2024:4469 access.redhat.com: https://access.redhat.com/errata/RHSA-2024:4474 access.redhat.com: https://access.redhat.com/errata/RHSA-2024:4479 access.redhat.com: https://access.redhat.com/errata/RHSA-2024:4484 access.redhat.com: https://access.redhat.com/security/cve/CVE-2024-6387 bugzilla.redhat.com: https://bugzilla.redhat.com/show_bug.cgi?id=2294604 santandersecurityresearch.github.io: https://santandersecurityresearch.github.io/blog/sshing_the_masses.html openssh.com: https://www.openssh.com/txt/release-9.8 qualys.com: https://www.qualys.com/2024/07/01/cve-2024-6387/regresshion.txt vicarius.io: https://www.vicarius.io/vsociety/posts/regresshion-an-openssh-regression-error-cve-2024-6387 exploit-db.com: https://www.exploit-db.com/exploits/52269 packetstorm.news: https://packetstorm.news/files/id/190587/ openwall.com: http://www.openwall.com/lists/oss-security/2024/07/01/12 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/01/13 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/02/1 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/03/1 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/03/11 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/03/2 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/03/3 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/03/4 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/03/5 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/04/1 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/04/2 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/08/2 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/08/3 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/09/2 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/09/5 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/10/1 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/10/2 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/10/3 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/10/4 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/10/6 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/11/1 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/11/3 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/23/4 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/23/6 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/28/2 openwall.com: http://www.openwall.com/lists/oss-security/2024/07/28/3 archlinux.org: https://archlinux.org/news/the-sshd-service-needs-to-be-restarted-after-upgrading-to-openssh-98p1/ arstechnica.com: https://arstechnica.com/security/2024/07/regresshion-vulnerability-in-openssh-gives-attackers-root-on-linux/ blog.qualys.com: https://blog.qualys.com/vulnerabilities-threat-research/2024/07/01/regresshion-remote-unauthenticated-code-execution-vulnerability-in-openssh-server explore.alas.aws.amazon.com: https://explore.alas.aws.amazon.com/CVE-2024-6387.html forum.vmssoftware.com: https://forum.vmssoftware.com/viewtopic.php?f=8&t=9132 ftp.netbsd.org: https://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2024-002.txt.asc github.com: https://github.com/AlmaLinux/updates/issues/629 github.com: https://github.com/Azure/AKS/issues/4379 github.com: https://github.com/PowerShell/Win32-OpenSSH/discussions/2248 github.com: https://github.com/PowerShell/Win32-OpenSSH/issues/2249 github.com: https://github.com/microsoft/azurelinux/issues/9555 github.com: https://github.com/openela-main/openssh/commit/e1f438970e5a337a17070a637c1b9e19697cad09 github.com: https://github.com/oracle/oracle-linux/issues/149 github.com: https://github.com/rapier1/hpn-ssh/issues/87 github.com: https://github.com/zgzhang/cve-2024-6387-poc lists.almalinux.org: https://lists.almalinux.org/archives/list/[email protected]/thread/23BF5BMGFVEVUI2WNVAGMLKT557EU7VY/ lists.mindrot.org: https://lists.mindrot.org/pipermail/openssh-unix-announce/2024-July/000158.html lists.mindrot.org: https://lists.mindrot.org/pipermail/openssh-unix-dev/2024-July/041431.html news.ycombinator.com: https://news.ycombinator.com/item?id=40843778 psirt.global.sonicwall.com: https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2024-0010 security-tracker.debian.org: https://security-tracker.debian.org/tracker/CVE-2024-6387 security.netapp.com: https://security.netapp.com/advisory/ntap-20240701-0001/ sig-security.rocky.page: https://sig-security.rocky.page/issues/CVE-2024-6387/ stackdiary.com: https://stackdiary.com/openssh-race-condition-in-sshd-allows-remote-code-execution/ ubuntu.com: https://ubuntu.com/security/CVE-2024-6387 ubuntu.com: https://ubuntu.com/security/notices/USN-6859-1 akamai.com: https://www.akamai.com/blog/security-research/2024-openssh-vulnerability-regression-what-to-know-and-do arista.com: https://www.arista.com/en/support/advisories-notices/security-advisory/19904-security-advisory-0100 freebsd.org: https://www.freebsd.org/security/advisories/FreeBSD-SA-24:04.openssh.asc splunk.com: https://www.splunk.com/en_us/blog/security/cve-2024-6387-regresshion-vulnerability.html suse.com: https://www.suse.com/security/cve/CVE-2024-6387.html theregister.com: https://www.theregister.com/2024/07/01/regresshion_openssh/ support.apple.com: https://support.apple.com/kb/HT214119 support.apple.com: https://support.apple.com/kb/HT214118 support.apple.com: https://support.apple.com/kb/HT214120 seclists.org: http://seclists.org/fulldisclosure/2024/Jul/20 seclists.org: http://seclists.org/fulldisclosure/2024/Jul/18 seclists.org: http://seclists.org/fulldisclosure/2024/Jul/19
Credits
Red Hat would like to thank Qualys Threat Research Unit (TRU) (Qualys) for reporting this issue.