CVE-2021-45712
📋 TL;DR
This vulnerability in the rust-embed crate allows directory traversal attacks in debug mode, potentially enabling attackers to read arbitrary files outside the intended directory. It affects Rust applications using rust-embed versions before 6.3.0 for embedding static files. The risk is primarily during development/debugging but could impact production if debug mode is enabled.
💻 Affected Systems
- rust-embed crate
📦 What is this software?
Rust Embed by Rust Embed Project
⚠️ Risk & Real-World Impact
Worst Case
Attackers could read sensitive files like configuration files, credentials, or source code from the filesystem, leading to data exposure or further exploitation.
Likely Case
Limited file disclosure during development/debugging sessions, potentially exposing development environment secrets or source code.
If Mitigated
No impact if debug mode is disabled or proper input validation is implemented.
🎯 Exploit Status
Directory traversal is a well-known attack pattern; exploitation requires debug mode and network access to the vulnerable application.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.3.0 and later
Vendor Advisory: https://rustsec.org/advisories/RUSTSEC-2021-0126.html
Restart Required: Yes
Instructions:
1. Update Cargo.toml to require rust-embed >=6.3.0. 2. Run 'cargo update' to fetch the patched version. 3. Rebuild and redeploy your application.
🔧 Temporary Workarounds
Disable debug mode
allEnsure applications are built and run in release mode, not debug mode.
cargo build --release
cargo run --release
Input validation
allImplement additional validation on file paths before passing to rust-embed functions.
🧯 If You Can't Patch
- Ensure all production deployments use release builds (not debug mode).
- Implement network segmentation to limit access to debug-mode applications.
🔍 How to Verify
Check if Vulnerable:
Check Cargo.lock or run 'cargo tree | grep rust-embed' to see if version is below 6.3.0.Check Version:
grep rust-embed Cargo.lockVerify Fix Applied:
Confirm rust-embed version is 6.3.0 or higher in Cargo.lock after update.📡 Detection & Monitoring
Log Indicators:
- Unusual file access patterns, especially with '../' sequences in paths
- Failed file access attempts outside expected directories
Network Indicators:
- HTTP requests containing '../' patterns to embedded file endpoints
SIEM Query:
source="application_logs" AND (path="*../*" OR message="*directory traversal*")🔗 References
- https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/rust-embed/RUSTSEC-2021-0126.md
- https://rustsec.org/advisories/RUSTSEC-2021-0126.html
- https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/rust-embed/RUSTSEC-2021-0126.md
- https://rustsec.org/advisories/RUSTSEC-2021-0126.html
