CVE-2020-35862
📋 TL;DR
This vulnerability in the Rust bitvec crate allows memory corruption through use-after-free or double-free errors when converting BitVec to BitBox. Any Rust application using vulnerable versions of the bitvec crate is affected, potentially leading to arbitrary code execution.
💻 Affected Systems
- Rust applications using bitvec crate
📦 What is this software?
Bitvec by Bitvec Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or ransomware deployment.
Likely Case
Application crashes, denial of service, or memory corruption leading to unpredictable behavior.
If Mitigated
Limited impact with proper memory protections and sandboxing, though crashes may still occur.
🎯 Exploit Status
Memory corruption vulnerabilities in Rust are particularly dangerous as they bypass Rust's memory safety guarantees.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: bitvec 0.17.4 or later
Vendor Advisory: https://rustsec.org/advisories/RUSTSEC-2020-0007.html
Restart Required: Yes
Instructions:
1. Update Cargo.toml to require bitvec >=0.17.4
2. Run 'cargo update' to fetch the patched version
3. Rebuild and redeploy your application
4. Restart any running services using the vulnerable version
🔧 Temporary Workarounds
Avoid BitVec to BitBox conversion
allModify code to avoid using the vulnerable conversion function
Pin bitvec version
allTemporarily pin to a safe version if immediate upgrade isn't possible
bitvec = "=0.17.3" # Note: This is NOT safe, only use if you can guarantee no BitBox conversion
🧯 If You Can't Patch
- Isolate vulnerable applications in containers or VMs with minimal privileges
- Implement strict input validation and sanitization for all user-provided data
🔍 How to Verify
Check if Vulnerable:
Check Cargo.lock or run 'cargo tree | grep bitvec' to see installed versionCheck Version:
grep bitvec Cargo.lock | head -5Verify Fix Applied:
Verify bitvec >=0.17.4 appears in Cargo.lock after update📡 Detection & Monitoring
Log Indicators:
- Application crashes with segmentation faults
- Memory corruption errors in Rust panic messages
- Unexpected process termination
Network Indicators:
- Unusual outbound connections from Rust applications
- Exploit attempts targeting memory corruption
SIEM Query:
process_name:your_rust_app AND (event_type:crash OR error_message:"double free" OR error_message:"use after free")