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CVE-2024-6409

high

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

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
7.0
7.0 (CVSS v3.1)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H
Severity source: NVD CVSS v3.1 (secalert@redhat.com)
Timeline (UTC)
Published: 2024-07-08 18:15
Modified: 2026-11-03 22:17
NVD status: Deferred
Last synced 1 day ago
Verified against the source API 2026-11-03 22:24 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

Not reported by the source (unknown — not "none").

Weakness classification (CWE)

CWE-364

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

No vendor advisory or patch reference tagged by NVD. Check the references below.

References

Data sources

NVD CVE API 2.0 — fetched 2026-11-03 22:24 UTC · record ↗

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