CVE-2021-45705
📋 TL;DR
This vulnerability in the nanorand Rust crate before version 0.6.1 allows multiple mutable references to the same object due to improper raw pointer dereferencing in the TlsWyRand Deref implementation. This violates Rust's ownership rules and can lead to data races, memory corruption, or undefined behavior. Any Rust application using vulnerable versions of the nanorand crate is affected.
💻 Affected Systems
- Rust applications using nanorand crate
📦 What is this software?
Nanorand by Nanorand Project
⚠️ Risk & Real-World Impact
Worst Case
Memory corruption leading to arbitrary code execution, denial of service, or data integrity compromise.
Likely Case
Application crashes, data corruption, or unpredictable behavior due to data races and memory safety violations.
If Mitigated
Limited impact if application doesn't heavily rely on thread-local random number generation or has additional memory safety controls.
🎯 Exploit Status
Exploitation requires understanding of Rust memory model and ability to trigger data races.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: nanorand 0.6.1 and later
Vendor Advisory: https://rustsec.org/advisories/RUSTSEC-2021-0114.html
Restart Required: Yes
Instructions:
1. Update Cargo.toml to require nanorand >= 0.6.1
2. Run 'cargo update' to fetch the patched version
3. Rebuild and redeploy your application
🔧 Temporary Workarounds
Pin to safe version
allManually specify nanorand version 0.6.1 or later in Cargo.toml
cargo update nanorand --precise 0.6.1
🧯 If You Can't Patch
- Avoid using TlsWyRand type in the nanorand crate
- Implement additional memory safety checks and bounds validation in application code
🔍 How to Verify
Check if Vulnerable:
Check Cargo.lock for nanorand version < 0.6.1Check Version:
grep nanorand Cargo.lockVerify Fix Applied:
Verify Cargo.lock shows nanorand >= 0.6.1📡 Detection & Monitoring
Log Indicators:
- Application crashes with memory access violations
- Unexpected behavior in random number generation
Network Indicators:
- None specific to this vulnerability
SIEM Query:
Application logs containing 'segmentation fault', 'memory access violation', or similar memory error messages