CVE-2021-28877
📋 TL;DR
This vulnerability in Rust's standard library before version 1.51.0 allows memory safety violations when using nested Zip iterators. The bug causes the same index to be accessed multiple times, potentially leading to use-after-free or other memory corruption issues. Any Rust application using nested Zip iterators is affected.
💻 Affected Systems
- Rust programming language standard library
📦 What is this software?
Rust by Rust Lang
⚠️ Risk & Real-World Impact
Worst Case
Memory corruption leading to arbitrary code execution, denial of service, or data corruption.
Likely Case
Application crashes or undefined behavior due to memory access violations.
If Mitigated
No impact if patched or if application doesn't use nested Zip iterators.
🎯 Exploit Status
Exploitation requires crafting specific iterator patterns to trigger the bug.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Rust 1.51.0 and later
Vendor Advisory: https://github.com/rust-lang/rust/pull/80670
Restart Required: Yes
Instructions:
1. Update Rust toolchain to version 1.51.0 or later using rustup. 2. Recompile all Rust applications with the updated toolchain. 3. Redeploy updated applications.
🔧 Temporary Workarounds
Avoid nested Zip iterators
allRefactor code to avoid using nested Zip iterators that could trigger the bug.
🧯 If You Can't Patch
- Implement input validation and sanitization for iterator operations
- Use memory-safe alternatives to Zip iterators in critical code paths
🔍 How to Verify
Check if Vulnerable:
Check Rust version with: rustc --version. If version is below 1.51.0, check code for nested Zip iterator usage.Check Version:
rustc --versionVerify Fix Applied:
Verify Rust version is 1.51.0 or higher: rustc --version. Test applications with previously problematic iterator patterns.📡 Detection & Monitoring
Log Indicators:
- Application crashes with memory access violations
- Segmentation faults in Rust applications
Network Indicators:
- Unusual application behavior after iterator operations
SIEM Query:
Process crashes with rustc or Rust application names