CVE-2020-2231
MEDIUMCVE-2020-2231 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in org.jenkins-ci.main:jenkins-core. 2 public exploit references exist, so weaponization risk is real. O3 Security confirms whether CVE-2020-2231 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Improper Neutralization of Input During Web Page Generation in Jenkins
Blast Radius
org.jenkins-ci.main:jenkins-core☕org.jenkins-ci.main:jenkins-coreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Jenkins 2.251 and earlier, LTS 2.235.3 and earlier does not escape the remote address of the host starting a build via 'Trigger builds remotely', resulting in a stored cross-site scripting (XSS) vulnerability exploitable by users with Job/Configure permission or knowledge of the Authentication Token.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.jenkins-ci.main:jenkins-core | all versions | 2.235.4 |
| ☕Maven | org.jenkins-ci.main:jenkins-core | ≥ 2.237&&< 2.252 | 2.252 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Jenkins 2.235.3 - 'X-Forwarded-For' Stored XSS
by gx1 · Dec 14, 2020
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.jenkins-ci.main:jenkins-core. 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 org.jenkins-ci.main:jenkins-core to 2.235.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-2231 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-2020-2231 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-2020-2231. 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-2020-2231 in your dependencies?
O3 detects CVE-2020-2231 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.