CVE-2025-32799
📋 TL;DR
CVE-2025-32799 is a path traversal vulnerability in conda-build that allows attackers to write files outside intended directories by crafting malicious tar archives. This can lead to arbitrary file overwrites, privilege escalation, or remote code execution. Users of conda-build versions before 25.4.0 are affected when processing untrusted tar archives.
💻 Affected Systems
- conda-build
📦 What is this software?
Conda Build by Anaconda
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with root privileges, complete system compromise, and lateral movement across networks.
Likely Case
Arbitrary file overwrites leading to privilege escalation or denial of service by corrupting critical system files.
If Mitigated
Limited to file writes in user-controlled directories if proper sandboxing and least privilege are enforced.
🎯 Exploit Status
Exploitation requires the attacker to supply a malicious tar archive that gets processed by conda-build. No authentication needed if the system processes external archives.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 25.4.0
Vendor Advisory: https://github.com/conda/conda-build/security/advisories/GHSA-h499-pxgj-qh5h
Restart Required: No
Instructions:
1. Update conda-build using: conda update conda-build
2. Or install specific version: conda install conda-build=25.4.0
3. Verify installation with: conda-build --version
🔧 Temporary Workarounds
Restrict tar archive sources
allOnly process tar archives from trusted sources and implement validation checks before extraction.
# Implement source validation in your build scripts
# Example: validate archive checksums before processing
Run in isolated environment
linuxExecute conda-build in containerized or sandboxed environments with restricted filesystem access.
docker run --read-only -v /safe/path:/data your-image
# Or use chroot/sandbox solutions
🧯 If You Can't Patch
- Implement strict input validation: reject tar archives containing path traversal sequences (../, ..\)
- Run conda-build with minimal privileges: use non-root users and restrict filesystem permissions
🔍 How to Verify
Check if Vulnerable:
Check conda-build version: conda-build --version. If version is less than 25.4.0, the system is vulnerable.Check Version:
conda-build --versionVerify Fix Applied:
After updating, verify version is 25.4.0 or higher: conda-build --version📡 Detection & Monitoring
Log Indicators:
- Unusual file write operations outside expected directories
- conda-build processing errors with malformed paths
- System logs showing privilege escalation attempts
Network Indicators:
- Downloads of tar archives from untrusted sources to build systems
- Unusual outbound connections from build systems post-processing
SIEM Query:
process_name:"conda-build" AND (file_write_path:"*../*" OR file_write_path:"*..\\*")🔗 References
- https://github.com/conda/conda-build/blob/834448b995eee02cf1c2e7ca97bcfa9affc77ee5/conda_build/convert.py
- https://github.com/conda/conda-build/blob/834448b995eee02cf1c2e7ca97bcfa9affc77ee5/conda_build/render.py
- https://github.com/conda/conda-build/commit/bdf5e0022cec9a0c1378cca3f2dc8c92b4834673
- https://github.com/conda/conda-build/security/advisories/GHSA-h499-pxgj-qh5h
- https://github.com/conda/conda-build/security/advisories/GHSA-h499-pxgj-qh5h
