CVE-2024-6409: Signal Handler Race Condition
CVE-2024-6409 is a race condition vulnerability in OpenSSH's server (sshd) signal handling. The issue arises when sshd's SIGALRM handler is called asynchronously if a remote attacker fails to authenticate within a set time. The signal handler invokes functions that are not async-signal-safe, such as syslog(), which can lead to a race condition. This vulnerability may allow remote code execution (RCE) as an unprivileged user running the sshd server. The vulnerability affects OpenSSH versions from 9.0 up to but not including 9.0.3. Red Hat has issued security advisories and updates addressing this flaw for Red Hat Enterprise Linux 9 and OpenShift Container Platform 4.16.4. The CVSS v3.1 base score is 7.0, indicating high severity. No known exploits in the wild have been reported at this time.
AI Analysis
Technical Summary
OpenSSH, the SSH protocol implementation used in Red Hat Enterprise Linux 9, contains a race condition in its signal handling code (CWE-364) that could lead to possible remote code execution (CVE-2024-6409). The vulnerability affects OpenSSH versions shipped with Red Hat Enterprise Linux 9 prior to the patched releases. Red Hat has released security advisories RHSA-2024:4457 and RHSA-2024:4716 providing updated OpenSSH packages that fix this issue. The CVSS score of 7.0 reflects a high severity with network attack vector, high attack complexity, no privileges required, no user interaction, and impacts on confidentiality, integrity, and availability. The vulnerability affects multiple architectures including x86_64, aarch64, ppc64le, and s390x. The vendor advisory confirms the availability of patches and provides detailed instructions for updating affected systems.
Potential Impact
The vulnerability could allow an unauthenticated remote attacker to execute arbitrary code on affected systems due to a race condition in signal handling within OpenSSH. This could compromise system confidentiality, integrity, and availability. The CVSS score of 7.0 (high severity) indicates significant risk if exploited. However, there are no known exploits in the wild at this time.
Mitigation Recommendations
Red Hat has released official security updates for OpenSSH that address CVE-2024-6409. Users running Red Hat Enterprise Linux 9 and its Extended Update Support versions should apply the provided OpenSSH package updates as soon as possible. Detailed update instructions are available in the Red Hat advisory and knowledge base article (https://access.redhat.com/articles/11258). No additional mitigations are specified beyond applying the official patches.
CVE-2024-6409: Signal Handler Race Condition
Description
CVE-2024-6409 is a race condition vulnerability in OpenSSH's server (sshd) signal handling. The issue arises when sshd's SIGALRM handler is called asynchronously if a remote attacker fails to authenticate within a set time. The signal handler invokes functions that are not async-signal-safe, such as syslog(), which can lead to a race condition. This vulnerability may allow remote code execution (RCE) as an unprivileged user running the sshd server. The vulnerability affects OpenSSH versions from 9.0 up to but not including 9.0.3. Red Hat has issued security advisories and updates addressing this flaw for Red Hat Enterprise Linux 9 and OpenShift Container Platform 4.16.4. The CVSS v3.1 base score is 7.0, indicating high severity. No known exploits in the wild have been reported at this time.
CVSS v3.1
Score 7.0high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
OpenSSH, the SSH protocol implementation used in Red Hat Enterprise Linux 9, contains a race condition in its signal handling code (CWE-364) that could lead to possible remote code execution (CVE-2024-6409). The vulnerability affects OpenSSH versions shipped with Red Hat Enterprise Linux 9 prior to the patched releases. Red Hat has released security advisories RHSA-2024:4457 and RHSA-2024:4716 providing updated OpenSSH packages that fix this issue. The CVSS score of 7.0 reflects a high severity with network attack vector, high attack complexity, no privileges required, no user interaction, and impacts on confidentiality, integrity, and availability. The vulnerability affects multiple architectures including x86_64, aarch64, ppc64le, and s390x. The vendor advisory confirms the availability of patches and provides detailed instructions for updating affected systems.
Potential Impact
The vulnerability could allow an unauthenticated remote attacker to execute arbitrary code on affected systems due to a race condition in signal handling within OpenSSH. This could compromise system confidentiality, integrity, and availability. The CVSS score of 7.0 (high severity) indicates significant risk if exploited. However, there are no known exploits in the wild at this time.
Mitigation Recommendations
Red Hat has released official security updates for OpenSSH that address CVE-2024-6409. Users running Red Hat Enterprise Linux 9 and its Extended Update Support versions should apply the provided OpenSSH package updates as soon as possible. Detailed update instructions are available in the Red Hat advisory and knowledge base article (https://access.redhat.com/articles/11258). No additional mitigations are specified beyond applying the official patches.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2024:4910
- Cve Count
- 1
Threat ID: 6a1f4ea0e29bf47b5008786c
Added to database: 06/02/2026, 21:44:00 UTC
Last enriched: 08/21/2026, 16:24:39 UTC
Last updated: 09/10/2026, 19:36:49 UTC
Views: 72
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