CVE-2023-33977
HIGHStored cross site scripting (XSS) via unrestricted file upload in Kiwi TCMS
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
kiwitcmsReal-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
Kiwi TCMS is an open source test management system for both manual and automated testing. Kiwi TCMS allows users to upload attachments to test plans, test cases, etc. Earlier versions of Kiwi TCMS had introduced upload validators in order to prevent potentially dangerous files from being uploaded and Content-Security-Policy definition to prevent cross-site-scripting attacks. The upload validation checks were not 100% robust which left the possibility to circumvent them and upload a potentially dangerous file which allows execution of arbitrary JavaScript in the browser. Additionally we've discovered that Nginx's proxy_pass directive will strip some headers negating protections built into Kiwi TCMS when served behind a reverse proxy. This issue has been addressed in version 12.4. Users are advised to upgrade. Users unable to upgrade who are serving Kiwi TCMS behind a reverse proxy should make sure that additional header values are still passed to the client browser. If they aren't redefining them inside the proxy configuration.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | kiwitcms | all versions | 12.4 |
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 kiwitcms. 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 kiwitcms to 12.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-33977 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 CVE-2023-33977 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 CVE-2023-33977. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-33977 in your dependencies?
O3 detects CVE-2023-33977 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.