CVE-2020-35876
📋 TL;DR
This vulnerability in the Rio crate for Rust allows attackers to leak structs, potentially exposing sensitive information, causing use-after-free conditions, or triggering data races. It affects all applications using vulnerable versions of the Rio crate. The high CVSS score indicates critical severity with broad impact potential.
💻 Affected Systems
- Rio crate for Rust
📦 What is this software?
Rio by Rio Project
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise through memory corruption leading to remote code execution, data exfiltration, or denial of service.
Likely Case
Application crashes, memory corruption, or sensitive data leakage affecting application stability and confidentiality.
If Mitigated
Limited impact with proper memory safety controls and sandboxing, but still potential for information disclosure.
🎯 Exploit Status
Exploitation requires crafting malicious input to trigger struct leakage. Memory corruption primitives are well-documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Rio crate 0.10.0 or later
Vendor Advisory: https://rustsec.org/advisories/RUSTSEC-2020-0021.html
Restart Required: Yes
Instructions:
1. Update Cargo.toml to require Rio crate >=0.10.0
2. Run 'cargo update' to fetch patched version
3. Rebuild and redeploy application
4. Restart affected services
🔧 Temporary Workarounds
Remove Rio dependency
allTemporarily remove Rio crate from project if not essential
cargo remove rio
Pin to safe version
allForce dependency to use patched version
rio = "^0.10.0"
🧯 If You Can't Patch
- Isolate vulnerable applications in network segments with strict access controls
- Implement application-level input validation and sanitization
🔍 How to Verify
Check if Vulnerable:
Check Cargo.lock or run 'cargo tree | grep rio' to see installed versionCheck Version:
grep -A2 -B2 rio Cargo.lockVerify Fix Applied:
Verify Rio crate version is >=0.10.0 in Cargo.lock after update📡 Detection & Monitoring
Log Indicators:
- Application crashes with memory access violations
- Unexpected memory allocation patterns
Network Indicators:
- Unusual outbound data transfers from affected applications
SIEM Query:
source="application_logs" AND ("segmentation fault" OR "use-after-free" OR "double free")