# CVE-2024-6409: Openssh: possible remote code execution due to a race condition in signal handling affecting red hat enterprise linux 9 > A race condition in OpenSSH's signal handling allows remote attackers to achieve code execution as an unprivileged user. - **Severity:** High 7.0 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 8 Jul 2024 - **Updated:** 15 Oct 2026 - **Also known as:** ALSA-2024:4457, CLSA-2024-1721929402, GHSA-79hg-h6r6-64mm, OESA-2024-1870, OESA-2024-1871, OESA-2024-1872, RHSA-2024:4457, RHSA-2024:4716, RHSA-2024:4910, RLSA-2024:4457 ## What is CVE-2024-6409? CVE-2024-6409 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 8 Jul 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official 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. Weakness: CWE-364 (Signal Handler Race Condition) ## Which versions are affected by CVE-2024-6409? | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `openssh` | AlmaLinux:9 | All versions | 8.7p1-38.el9_4.4 | | `openssh-askpass` | AlmaLinux:9 | All versions | 8.7p1-38.el9_4.4 | | `openssh-clients` | AlmaLinux:9 | All versions | 8.7p1-38.el9_4.4 | | `openssh-keycat` | AlmaLinux:9 | All versions | 8.7p1-38.el9_4.4 | | `openssh-server` | AlmaLinux:9 | All versions | 8.7p1-38.el9_4.4 | | `pam_ssh_agent_auth` | AlmaLinux:9 | All versions | 0.10.4-5.38.el9_4.4 | | `openssh-askpass` | Red Hat:enterprise_linux:9::appstream | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-askpass-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-clients-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-debugsource` | Red Hat:enterprise_linux:9::appstream | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-keycat-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-server-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-sk-dummy-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:8.7p1-38.el9_4.4 | | `pam_ssh_agent_auth` | Red Hat:enterprise_linux:9::appstream | All versions | 0:0.10.4-5.38.el9_4.4 | | `pam_ssh_agent_auth-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:0.10.4-5.38.el9_4.4 | | `openssh` | Red Hat:enterprise_linux:9::baseos | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-askpass-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-clients` | Red Hat:enterprise_linux:9::baseos | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-clients-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-debugsource` | Red Hat:enterprise_linux:9::baseos | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-keycat` | Red Hat:enterprise_linux:9::baseos | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-keycat-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-server` | Red Hat:enterprise_linux:9::baseos | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-server-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:8.7p1-38.el9_4.4 | | `openssh-sk-dummy-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:8.7p1-38.el9_4.4 | | `pam_ssh_agent_auth-debuginfo` | Red Hat:enterprise_linux:9::baseos | All versions | 0:0.10.4-5.38.el9_4.4 | | `openssh-askpass` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:8.7p1-12.el9_0.3 | | `openssh-askpass-debuginfo` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:8.7p1-12.el9_0.3 | | `openssh-clients-debuginfo` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:8.7p1-12.el9_0.3 | | `openssh-debuginfo` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:8.7p1-12.el9_0.3 | | `openssh-debugsource` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:8.7p1-12.el9_0.3 | | `openssh-keycat-debuginfo` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:8.7p1-12.el9_0.3 | | `openssh-server-debuginfo` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:8.7p1-12.el9_0.3 | | `pam_ssh_agent_auth` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:0.10.4-4.12.el9_0.3 | | `pam_ssh_agent_auth-debuginfo` | Red Hat:rhel_e4s:9.0::appstream | All versions | 0:0.10.4-4.12.el9_0.3 | | `openssh` | Red Hat:rhel_e4s:9.0::baseos | All versions | 0:8.7p1-12.el9_0.3 | | `openssh-askpass-debuginfo` | Red Hat:rhel_e4s:9.0::baseos | All versions | 0:8.7p1-12.el9_0.3 | | `openssh-clients` | Red Hat:rhel_e4s:9.0::baseos | All versions | 0:8.7p1-12.el9_0.3 | ## How do I fix CVE-2024-6409? Apply the vendor's patch. ## Is CVE-2024-6409 being exploited? There is no known exploitation of CVE-2024-6409 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2024-6409 and fix it if it is affected. What it is: CVE-2024-6409 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 8 Jul 2024. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2024-6409 in the wild and no public exploit code. Affected product: Red Hat Enterprise Linux 10. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2024-6409/ (Markdown: https://insights.sbomify.com/CVE-2024-6409/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2024-6409 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-6409 - OSV: https://osv.dev/vulnerability/CVE-2024-6409 --- From sbomify Insights: https://insights.sbomify.com/CVE-2024-6409/ Summaries are generated and may contain mistakes; the official description above is the record.