CVE-2024-11218: Podman & Buildah Race Condition Vulnerability

CVE-2024-11218 Overview

A container breakout vulnerability was discovered in podman build and buildah that allows attackers to escape container isolation through a race condition. The vulnerability is triggered when using the --jobs=2 flag during container image builds with a maliciously crafted Containerfile. While SELinux can provide some mitigation, even with SELinux enabled, the vulnerability still permits enumeration of files and directories on the host system, potentially exposing sensitive information and allowing further exploitation.

Critical Impact

This vulnerability enables container escape with potential for host file system enumeration and access, undermining container isolation security guarantees.

Affected Products

• Podman (podman build functionality)
• Buildah (container image building tool)
• Red Hat Enterprise Linux and related distributions using affected versions

Discovery Timeline

• January 22, 2025 - CVE-2024-11218 published to NVD
• October 2, 2025 - Last updated in NVD database

Technical Details for CVE-2024-11218

Vulnerability Analysis

This vulnerability represents a container breakout attack that exploits improper privilege management (CWE-269) in the parallel build functionality of podman and buildah. The attack requires local access and user interaction, as a victim must build a maliciously crafted Containerfile. When the --jobs=2 parameter is specified, enabling parallel build operations, a race condition window opens that can be exploited to break out of container isolation.

The race condition occurs during the parallel execution of build stages, where timing-sensitive operations can be manipulated to gain access beyond the container boundary. Even on systems with SELinux enforcing, which would normally restrict such access, the vulnerability still permits file and directory enumeration on the host system, providing attackers with reconnaissance capabilities.

Root Cause

The root cause is improper privilege management during parallel container build operations. When multiple build jobs execute concurrently via the --jobs flag, synchronization flaws in the build process create a time-of-check time-of-use (TOCTOU) style race condition. This allows carefully timed operations in a malicious Containerfile to access resources outside the intended container scope before proper isolation enforcement occurs.

Attack Vector

The attack requires an attacker to craft a malicious Containerfile specifically designed to exploit the race condition timing window. The attack flow is as follows:

1. Attacker creates a Containerfile with instructions designed to trigger the race condition
2. Victim executes podman build --jobs=2 or buildah build --jobs=2 with the malicious Containerfile
3. During parallel build execution, the race condition allows operations to escape container isolation
4. Even with SELinux enabled, file and directory enumeration on the host becomes possible

The vulnerability is particularly concerning in CI/CD environments where automated builds may process untrusted Containerfiles, or in development environments where users routinely build container images from various sources.

Detection Methods for CVE-2024-11218

Indicators of Compromise

• Unexpected file access patterns originating from podman or buildah processes outside container scope
• Unusual parallel build operations with --jobs flag in environments where it's not normally used
• SELinux AVC denials related to container build processes attempting to access host resources
• Build logs showing unexpected host file system enumeration or access attempts

Detection Strategies

• Monitor for podman and buildah processes using the --jobs flag, especially with values greater than 1
• Implement audit logging for container build operations to detect suspicious Containerfile content
• Enable SELinux audit logging to capture potential exploitation attempts even when SELinux blocks the attack
• Review CI/CD pipeline logs for builds involving untrusted or externally sourced Containerfiles

Monitoring Recommendations

• Configure audit rules to track podman and buildah invocations with parallel job parameters
• Implement container runtime security monitoring to detect anomalous file access during build operations
• Set up alerts for SELinux denials involving container build processes
• Monitor for unusual directory traversal or enumeration activities during container image builds

How to Mitigate CVE-2024-11218

Immediate Actions Required

• Update podman and buildah to the latest patched versions available from your distribution
• Avoid using the --jobs flag with values greater than 1 until systems are patched
• Enable SELinux in enforcing mode to limit the impact of potential exploitation
• Review and audit any Containerfiles from untrusted sources before building

Patch Information

Red Hat has released multiple security advisories addressing this vulnerability across various Red Hat Enterprise Linux versions and related products. Key advisories include RHSA-2025:0830, RHSA-2025:0878, and RHSA-2025:0922. The fix has been implemented in buildah via GitHub PR #5918. Organizations should consult the Red Hat CVE page for CVE-2024-11218 for the complete list of affected products and available patches.

Workarounds

• Disable parallel builds by removing the --jobs flag or explicitly setting --jobs=1
• Ensure SELinux is enabled and enforcing to limit the scope of potential exploitation
• Restrict container builds to trusted Containerfiles only in production environments
• Implement network segmentation and access controls around build systems processing external content

# Disable parallel builds as a workaround
# Instead of:
# podman build --jobs=2 -t myimage .

# Use single-threaded builds:
podman build --jobs=1 -t myimage .

# Or omit the --jobs flag entirely:
podman build -t myimage .

# Verify SELinux is enforcing:
getenforce
# If not enforcing, enable it:
sudo setenforce 1