GHSA-j3q4-gmj4-mj95 is a critical-severity (CVSS 9.8) CWE-384 vulnerability in rdiffweb. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether GHSA-j3q4-gmj4-mj95 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
rdiffweb vulnerable to account access via session fixation
Real-World Exposure
rdiffwebReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
rdiffweb prior to 2.4.7 fails to invalidate session cookies on logout, leading to session fixation and allowing an attacker to access a users account. After logging in and logging out, the application continues to use the preauthentication cookies. The cookies remain the same after closing the browser and after password reset. The same cookies are reassigned for additional user logins which can lead to session fixation. An attacker can gain unauthorized access to the account of users who are using the same browser as long as a single session cookie persists on that browser once the attacker obtains a session cookie through another attack. This issue is patched in version 2.4.7. There are no known workarounds.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | rdiffweb | all versions | 2.4.7 |
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 rdiffweb. 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 rdiffweb to 2.4.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j3q4-gmj4-mj95 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-j3q4-gmj4-mj95 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-j3q4-gmj4-mj95. 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-j3q4-gmj4-mj95 in your dependencies?
O3 detects GHSA-j3q4-gmj4-mj95 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.