CVE-2025-58058
📋 TL;DR
This vulnerability in the xz Go package allows attackers to prepend arbitrary data before LZMA-encoded streams, causing excessive memory allocation during header parsing. Systems using xz versions before 0.5.14 for processing untrusted xz files are affected. The issue stems from missing validation in the LZMA header parsing logic.
💻 Affected Systems
- ulikunitz/xz Go package
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Denial of service through memory exhaustion leading to application crashes or system instability when processing malicious xz files.
Likely Case
Increased memory consumption causing performance degradation or application crashes when processing malformed xz files.
If Mitigated
Minimal impact with proper input validation and memory limits in place.
🎯 Exploit Status
Exploitation requires the ability to provide malicious xz files to vulnerable applications.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.5.14
Vendor Advisory: https://github.com/ulikunitz/xz/security/advisories/GHSA-jc7w-c686-c4v9
Restart Required: Yes
Instructions:
1. Update Go dependencies: go get github.com/ulikunitz/xz@v0.5.14
2. Update go.mod to require version 0.5.14
3. Rebuild and redeploy affected applications
4. Restart services using the updated package
🔧 Temporary Workarounds
Input validation wrapper
allImplement custom validation to check xz file integrity before processing
// Go code to validate xz files before processing
// Check file size limits and implement custom header validation
Memory limit enforcement
allSet memory limits on processes handling xz file decompression
// In Go: Use runtime/debug.SetMemoryLimit()
// System: ulimit -v [memory_limit_in_kb]
🧯 If You Can't Patch
- Implement strict file size limits for xz file uploads/processing
- Isolate xz processing to containers with memory limits and restart policies
🔍 How to Verify
Check if Vulnerable:
Check go.mod or vendor dependencies for xz version: grep 'ulikunitz/xz' go.modCheck Version:
go list -m github.com/ulikunitz/xzVerify Fix Applied:
Verify xz version is 0.5.14 or later: go list -m github.com/ulikunitz/xz📡 Detection & Monitoring
Log Indicators:
- Sudden memory spikes in applications processing xz files
- Application crashes during xz file processing
- High memory allocation errors in logs
Network Indicators:
- Unusually large xz file uploads to vulnerable endpoints
SIEM Query:
source="application_logs" AND ("memory allocation failed" OR "out of memory") AND process="*xz*"