CVE-2023-45842
📋 TL;DR
This CVE describes data integrity vulnerabilities in Buildroot's package hash checking functionality that allow man-in-the-middle attackers to execute arbitrary commands on the builder system. Attackers can intercept package downloads and replace them with malicious versions, leading to remote code execution. This affects Buildroot users who download packages over untrusted networks.
💻 Affected Systems
- Buildroot
📦 What is this software?
Buildroot by Buildroot
⚠️ Risk & Real-World Impact
Worst Case
Full compromise of the build system leading to supply chain attacks, backdoored firmware/images, and lateral movement to connected systems.
Likely Case
Attackers intercept package downloads over unsecured networks to execute arbitrary code on build servers, potentially compromising build artifacts.
If Mitigated
Limited impact if using secure transport (HTTPS/TLS), package signing verification, and isolated build environments.
🎯 Exploit Status
Requires man-in-the-middle position on network traffic, but no authentication needed to trigger the vulnerable code path.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Buildroot security updates after 2023.08.1
Vendor Advisory: https://buildroot.org/downloads/security/
Restart Required: No
Instructions:
1. Update Buildroot to latest patched version. 2. Rebuild affected packages. 3. Verify package hashes are properly validated.
🔧 Temporary Workarounds
Use HTTPS/TLS for package downloads
linuxConfigure Buildroot to download packages only over HTTPS to prevent MITM attacks
Modify BR2_PRIMARY_SITE to use https:// URLs in build configuration
Enable package signature verification
linuxUse Buildroot's package signing features to verify package integrity
Set BR2_GPG_ENABLED=y and configure appropriate GPG keys
🧯 If You Can't Patch
- Isolate build systems from untrusted networks using air-gapped or controlled network segments
- Implement network monitoring and intrusion detection for build server traffic
🔍 How to Verify
Check if Vulnerable:
Check Buildroot version: grep 'BR2_VERSION' .config or check buildroot version fileCheck Version:
grep 'BR2_VERSION' .config 2>/dev/null || cat .config | grep VERSIONVerify Fix Applied:
Verify package downloads use HTTPS and hash verification is enabled in build logs📡 Detection & Monitoring
Log Indicators:
- Failed hash verification warnings
- Unexpected package downloads from non-HTTPS sources
- Unusual build process executions
Network Indicators:
- HTTP package downloads instead of HTTPS
- Unencrypted traffic to package repositories
SIEM Query:
source="buildroot.log" AND ("hash mismatch" OR "download failed" OR "http://" AND "download")🔗 References
- http://www.openwall.com/lists/oss-security/2023/12/11/1
- https://talosintelligence.com/vulnerability_reports/TALOS-2023-1844
- http://www.openwall.com/lists/oss-security/2023/12/11/1
- https://talosintelligence.com/vulnerability_reports/TALOS-2023-1844
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2023-1844
