CVE-2024-21626
Description
A file descriptor leak issue was found in the runc package. While a user performs O_CLOEXEC all file descriptors before executing the container code, the file descriptor is open when performing setcwd(2), which means that the reference can be kept alive in the container by configuring the working directory to be a path resolved through the file descriptor. The non-dumpable bit is unset after execve, meaning there are multiple ways to attack this other than bad configurations. The only way to defend against it entirely is to close all unneeded file descriptors.
Security Bulletin
Statement
These vulnerabilities not only enable malicious actors to escape containerized environments but also allow for full control over the underlying host system. With the widespread adoption of containerization technologies in both development and production environments, such exploits pose significant risks to data integrity, confidentiality, and system stability.
OpenShift Container Platform ships with SELinux in targeted enforcing mode, which prevents the container processes from accessing host content and mitigates this attack, and disabling SELinux on the Openshift container platform is not supported. Hence, the impact of the Openshift Container Platform is reduced to Moderate.
For multicluster-engine (MCE) vulnerable versions of buildkit and runc are part of installed version of oc. However, they are not affecting the higher-level assisted-installer binary in MCE. The presence of these dependencies in the container does not imply a security risk to the containerized application itself, as it is based on low-level packages included in the oc binary, and the impact to the container's core functionality is minimal.
This flaw doesn't affect the OpenShift Tools & Services as the affected code is only used for testing and is not exposed to the final user.
Mitigation
Red Hat Enterprise Linux (RHEL) and OpenShift ships with SELinux in targeted enforcing mode, which prevents the container processes from accessing host content and mitigates this attack. Dockerfiles can be inspected on the 'RUN' and 'WORKDIR' directives to ensure that there are no escapes or malicious paths, which are an indication of compromise. Limiting access and only using trusted container images can help prevent unauthorized access and malicious attacks.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.6 | 8.6 | 8.6 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | Required | Required | Required |
| Scope | Changed | Changed | Changed |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Acknowledgements
Red Hat would like to thank The Snyk Reseacher Team for reporting this issue.
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