CVE-2020-35902
📋 TL;DR
This vulnerability in the actix-codec crate for Rust allows attackers to exploit a use-after-free memory corruption flaw in the Framed component. This could lead to remote code execution, denial of service, or information disclosure. Any Rust application using vulnerable versions of actix-codec is affected.
💻 Affected Systems
- actix-codec crate for Rust
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with full system compromise, allowing attackers to execute arbitrary code on affected systems.
Likely Case
Application crash leading to denial of service, potentially with memory corruption that could be leveraged for further exploitation.
If Mitigated
Limited impact if proper memory safety controls and sandboxing are implemented, though application instability may still occur.
🎯 Exploit Status
Use-after-free vulnerabilities are commonly exploited in memory corruption attacks. The public advisory includes technical details that could facilitate exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.3.0-beta.1 and later
Vendor Advisory: https://rustsec.org/advisories/RUSTSEC-2020-0049.html
Restart Required: Yes
Instructions:
1. Update Cargo.toml to require actix-codec >= 0.3.0-beta.1
2. Run 'cargo update' to fetch the patched version
3. Rebuild and redeploy your application
4. Restart any running services using the updated application
🔧 Temporary Workarounds
Remove actix-codec dependency
allIf possible, remove or replace the actix-codec dependency with an alternative implementation
cargo remove actix-codec
🧯 If You Can't Patch
- Isolate affected applications in network segments with strict firewall rules
- Implement application-level firewalls or WAFs to monitor and block suspicious traffic patterns
🔍 How to Verify
Check if Vulnerable:
Check Cargo.lock or run 'cargo tree | grep actix-codec' to see if version < 0.3.0-beta.1 is presentCheck Version:
cargo tree | grep actix-codecVerify Fix Applied:
Run 'cargo tree | grep actix-codec' and verify version is >= 0.3.0-beta.1📡 Detection & Monitoring
Log Indicators:
- Application crashes with segmentation faults
- Unexpected memory access errors in Rust panic messages
- Abnormal termination of actix-web services
Network Indicators:
- Unusual network patterns to services using actix-codec
- Exploit attempts targeting Rust web services
SIEM Query:
source="application_logs" AND ("segmentation fault" OR "use-after-free" OR "actix-codec" OR "RUSTSEC-2020-0049")