VulnerabilityDeferred

CVE-2024-6409

A race condition vulnerability was discovered in how signals are handled by OpenSSH's server (sshd).

HIGH 7.0EPSS 27.9%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 27.9%, higher than 98% of all known CVEs. Patch or mitigate before the next change window.

Description

A race condition vulnerability was discovered in how signals are handled by OpenSSH's server (sshd). If a remote attacker does not authenticate within a set time period, then sshd's SIGALRM handler is called asynchronously. However, this signal handler calls various functions that are not async-signal-safe, for example, syslog(). As a consequence of a successful attack, in the worst case scenario, an attacker may be able to perform a remote code execution (RCE) as an unprivileged user running the sshd server.

CVSS 3.1: 7.0 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H
EPSS: 27.93% probability · 98th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-364
Source: secalert@redhat.com

EPSS trend

EPSS 27.9% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.