CVE-2020-27216
HIGHCVE-2020-27216 is a high-severity (CVSS 7) CWE-378 vulnerability in org.eclipse.jetty:jetty-webapp. 2 public exploit references exist, so weaponization risk is real. O3 Security confirms whether CVE-2020-27216 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Local Temp Directory Hijacking Vulnerability
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.
How urgent is this, really
CVE-2020-27216 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 0 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.eclipse.jetty:jetty-webapp☕org.mortbay.jetty:jetty-webapp☕org.eclipse.jetty:jetty-webapp☕org.mortbay.jetty:jetty-webapp☕org.eclipse.jetty:jetty-webapp☕org.mortbay.jetty:jetty-webappReal-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
In Eclipse Jetty versions 1.0 thru 9.4.32.v20200930, 10.0.0.alpha1 thru 10.0.0.beta2, and 11.0.0.alpha1 thru 11.0.0.beta2O, on Unix like systems, the system's temporary directory is shared between all users on that system. A collocated user can observe the process of creating a temporary sub directory in the shared temporary directory and race to complete the creation of the temporary subdirectory. If the attacker wins the race then they will have read and write permission to the subdirectory used to unpack web applications, including their WEB-INF/lib jar files and JSP files. If any code is ever executed out of this temporary directory, this can lead to a local privilege escalation vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.eclipse.jetty:jetty-webapp | all versions | 9.4.33.v20201020 |
| ☕Maven | org.mortbay.jetty:jetty-webapp | all versions | 9.4.33 |
| ☕Maven | org.eclipse.jetty:jetty-webapp | ≥ 10.0.0.beta1&&< 10.0.0.beta3 | 10.0.0.beta3 |
| ☕Maven | org.mortbay.jetty:jetty-webapp | ≥ 10.0.0.beta1&&< 10.0.0.beta3 | 10.0.0.beta3 |
| ☕Maven | org.eclipse.jetty:jetty-webapp | ≥ 11.0.0.beta1&&< 11.0.0.beta3 | 11.0.0.beta3 |
| ☕Maven | org.mortbay.jetty:jetty-webapp | ≥ 11.0.0.beta1&&< 11.0.0.beta3 | 11.0.0.beta3 |
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 org.eclipse.jetty:jetty-webapp. 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.eclipse.jetty:jetty-webapp to 9.4.33.v20201020 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-27216 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-2020-27216 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-2020-27216. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
In OpenShift Container Platform (OCP), the Hive/Presto/Hadoop components that comprise the OCP Metering stack, ship the vulnerable version of jetty. Since the release of OCP 4.6, the Metering product has been deprecated [1], hence the affected components are marked as wontfix. This may be fixed in the future. [1]…
Frequently Asked Questions
Is CVE-2020-27216 in your dependencies?
O3 detects CVE-2020-27216 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.