OpenSSH pre-authentication async signal safety issue
Priority MEDIUM 41CWE-364Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA.
Summary
A signal handler in sshd(8) may call a logging function that is not async-signal-safe. The signal handler is invoked when a client does not authenticate within the LoginGraceTime seconds (120 by default). This signal handler executes in the context of the sshd(8)'s privileged code, which is not sandboxed and runs with full root privileges. This issue is another instance of the problem in CVE-2024-6387 addressed by FreeBSD-SA-24:04.openssh. The faulty code in this case is from the integration of blacklistd in OpenSSH in FreeBSD. As a result of calling functions that are not async-signal-safe in the privileged sshd(8) context, a race condition exists that a determined attacker may be able to exploit to allow an unauthenticated remote code execution as root.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.02038 81st percentileScored 2026-11-07
Fix Fixed FreeBSD (FreeBSD): p3, p9, p5
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| FreeBSD | FreeBSD | 14.1-RELEASE to before p3; 14.0-RELEASE to before p9; 13.3-RELEASE to before p5 | p3, p9, p5 | Patch available | CNA |
- FreeBSD VendorFreeBSD Affected 14.1-RELEASE to before p3; 14.0-RELEASE to before p9; 13.3-RELEASE to before p5 Fixed in p3, p9, p5 Patch available CNA
CPE configurations NVD · 18
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:freebsd:freebsd:*:*:*:*:*:*:*:* | before 13.0; 13.1 to before 13.3 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:13.3:p1:*:*:*:*:*:* | 13.3 p1 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:13.3:p2:*:*:*:*:*:* | 13.3 p2 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:13.3:p3:*:*:*:*:*:* | 13.3 p3 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:13.3:p4:*:*:*:*:*:* | 13.3 p4 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:14.0:beta5:*:*:*:*:*:* | 14.0 beta5 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:14.0:p1:*:*:*:*:*:* | 14.0 p1 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:14.0:p2:*:*:*:*:*:* | 14.0 p2 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:14.0:p3:*:*:*:*:*:* | 14.0 p3 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:14.0:p4:*:*:*:*:*:* | 14.0 p4 | Vulnerable | FreeBSD |
- cpe:2.3:o:freebsd:freebsd:*:*:*:*:*:*:*:* Versions before 13.0; 13.1 to before 13.3 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:13.3:p1:*:*:*:*:*:* Versions 13.3 p1 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:13.3:p2:*:*:*:*:*:* Versions 13.3 p2 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:13.3:p3:*:*:*:*:*:* Versions 13.3 p3 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:13.3:p4:*:*:*:*:*:* Versions 13.3 p4 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:14.0:beta5:*:*:*:*:*:* Versions 14.0 beta5 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:14.0:p1:*:*:*:*:*:* Versions 14.0 p1 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:14.0:p2:*:*:*:*:*:* Versions 14.0 p2 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:14.0:p3:*:*:*:*:*:* Versions 14.0 p3 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:14.0:p4:*:*:*:*:*:* Versions 14.0 p4 Vulnerable ·FreeBSD
Show 8 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:freebsd:freebsd:14.0:p5:*:*:*:*:*:* | 14.0 p5 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:14.0:p6:*:*:*:*:*:* | 14.0 p6 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:14.0:p7:*:*:*:*:*:* | 14.0 p7 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:14.0:p8:*:*:*:*:*:* | 14.0 p8 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:14.0:rc3:*:*:*:*:*:* | 14.0 rc3 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:14.0:rc4-p1:*:*:*:*:*:* | 14.0 rc4-p1 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:14.1:p1:*:*:*:*:*:* | 14.1 p1 | Vulnerable | FreeBSD |
| cpe:2.3:o:freebsd:freebsd:14.1:p2:*:*:*:*:*:* | 14.1 p2 | Vulnerable | FreeBSD |
- cpe:2.3:o:freebsd:freebsd:14.0:p5:*:*:*:*:*:* Versions 14.0 p5 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:14.0:p6:*:*:*:*:*:* Versions 14.0 p6 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:14.0:p7:*:*:*:*:*:* Versions 14.0 p7 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:14.0:p8:*:*:*:*:*:* Versions 14.0 p8 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:14.0:rc3:*:*:*:*:*:* Versions 14.0 rc3 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:14.0:rc4-p1:*:*:*:*:*:* Versions 14.0 rc4-p1 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:14.1:p1:*:*:*:*:*:* Versions 14.1 p1 Vulnerable ·FreeBSD
- cpe:2.3:o:freebsd:freebsd:14.1:p2:*:*:*:*:*:* Versions 14.1 p2 Vulnerable ·FreeBSD
Remediation
- Fix · CNA FreeBSD (FreeBSD) Fixed in p3, p9, p5
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
FreeBSD p3, p5, p9
4 records Highest priority Priority MEDIUM 1 MEDIUM, 3 LOW
Other records, highest priority first
- TI-2024-06267 ktrace(2) fails to detach when executing a setuid binaryPriority LOW 34
- TI-2024-06266 NFS client accepts file names containing path separatorsPriority LOW 31
- TI-2024-06157 pf incorrectly matches different ICMPv6 states in the state tablePriority LOW 28
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
Not affected: 6 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-02 Threatist record created from CVE-2024-7589
- 2026-10-03 Alias added: GHSA-j7jm-6q5x-ffr4
References
More Freebsd vulnerabilities
- TI-2011-04182 Buffer overflow in libtelnet/encrypt.c in telnetd in FreeBSD 7.3 through 9.0, MIT… CVSS 2.0HIGH 10.0
- TI-2007-03684 Integer overflow in print-bgp.c in the BGP dissector in tcpdump 3.9.6 and earlier allows… CVSS 3.1CRITICAL 9.8
- TI-2002-00376 Integer overflow in xdr_array function in RPC servers for operating systems that use… CVSS 3.1CRITICAL 9.8
- TI-2024-05929 Openssh: regresshion - race condition in ssh allows rce/dos CVSS 3.1HIGH 8.1
- TI-2003-00437 Off-by-one error in the fb_realpath() function, as derived from the realpath function in… CVSS 3.1CRITICAL 9.8
- TI-2003-00642 The prescan function in Sendmail 8.12.9 allows remote attackers to execute arbitrary code… CVSS 2.0HIGH 10.0
Sources
- CVE-2024-7589 · CVE Program
- CVE-2024-7589 · NVD
- FIRST EPSS
- GHSA-j7jm-6q5x-ffr4 · GitHub Advisory Database · CC BY 4.0
- CVE-2024-7589 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences