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Vulnerability · Published Jul 8, 2024 · Assigned by redhat

CVE-2024-6409Openssh: possible remote code execution due to a race condition in signal handling affecting red hat enterprise linux 9

High 7.0

In plain English

A high-severity security flaw in OpenSSH. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 27.9% (higher than 98% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.0High
Exploit odds (30 days)27.9%top 1.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:9openssh8.7p1-38.el9_4.4ALSA-2024:4457
AlmaLinux:9openssh-askpass8.7p1-38.el9_4.4ALSA-2024:4457
AlmaLinux:9openssh-clients8.7p1-38.el9_4.4ALSA-2024:4457
AlmaLinux:9openssh-keycat8.7p1-38.el9_4.4ALSA-2024:4457
AlmaLinux:9openssh-server8.7p1-38.el9_4.4ALSA-2024:4457
AlmaLinux:9pam_ssh_agent_auth0.10.4-5.38.el9_4.4ALSA-2024:4457
Rocky Linux:9openssh0:8.7p1-38.el9_4.4RLSA-2024:4457

Affected products (as reported)

VendorProductVersions
OpenSSH see references
Red Hat Red Hat Enterprise Linux 9 see references
Red Hat Red Hat Enterprise Linux 9 see references
Red Hat Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions see references
Red Hat Red Hat Enterprise Linux 9.2 Extended Update Support see references
Red Hat Red Hat OpenShift Container Platform 4.13 see references
Red Hat Red Hat OpenShift Container Platform 4.14 see references
Red Hat Red Hat OpenShift Container Platform 4.15 see references
Red Hat Red Hat OpenShift Container Platform 4.16 see references
Red Hat Red Hat Enterprise Linux 10 see references
Red Hat Red Hat Enterprise Linux 6 see references
Red Hat Red Hat Enterprise Linux 7 see references
Red Hat Red Hat Enterprise Linux 8 see references

Weakness: CWE-364 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H

References