GHSA-qc36-q22q-cjw3
CRITICALSMTP command injection in lettre
Blast Radius
lettreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Affected versions of lettre allowed SMTP command injection through an attacker's controlled message body. The module for escaping lines starting with a period wouldn't catch a period that was placed after a double CRLF sequence, allowing the attacker to end the current message and write arbitrary SMTP commands after it.
Fix
The flaw is fixed by correctly handling consecutive CRLF sequences.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | lettre | ≥ 0.7.0&&< 0.9.6 | 0.9.6 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for lettre. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update lettre to 0.9.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-qc36-q22q-cjw3 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-qc36-q22q-cjw3 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-qc36-q22q-cjw3. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-qc36-q22q-cjw3 in your dependencies?
O3 detects GHSA-qc36-q22q-cjw3 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.