CVE-2020-13935
HIGHInfinite Loop in Apache Tomcat
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
org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcat☕org.apache.tomcat:tomcatReal-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
The payload length in a WebSocket frame was not correctly validated in Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M1 to 9.0.36, 8.5.0 to 8.5.56 and 7.0.27 to 7.0.104. Invalid payload lengths could trigger an infinite loop. Multiple requests with invalid payload lengths could lead to a denial of service.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.tomcat:tomcat | ≥ 10.0.0-M1&&< 10.0.0-M7 | 10.0.0-M7 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 9.0.0.M1&&< 9.0.37 | 9.0.37 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 8.5.0&&< 8.5.57 | 8.5.57 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 7.0.27&&< 7.0.105 | 7.0.105 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Frequently Asked Questions
Is CVE-2020-13935 in your stack?
O3 detects CVE-2020-13935 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.