CVE-2021-30640 — tomcat
MEDIUMCVE-2021-30640 is a medium-severity (CVSS 6.5) CWE-116 vulnerability in org.apache.tomcat:tomcat. A fix is available for org.apache.tomcat:tomcat — see the affected versions and patch details below.
Authentication Bypass by Alternate Name in Apache Tomcat
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2021-30640.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-30640 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,987 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
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
A vulnerability in the JNDI Realm of Apache Tomcat allows an attacker to authenticate using variations of a valid user name and/or to bypass some of the protection provided by the LockOut Realm. This issue affects Apache Tomcat 10.0.0-M1 to 10.0.5; 9.0.0.M1 to 9.0.45; 8.5.0 to 8.5.65.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.tomcat:tomcat | ≥ 10.0.0-M1&&< 10.0.5 | 10.0.5org.apache.tomcat:tomcat:10.0.5 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 9.0.0M1&&< 9.0.45 | 9.0.45org.apache.tomcat:tomcat:9.0.45 |
| ☕Maven | org.apache.tomcat:tomcat | ≥ 8.5.0&&< 8.5.65 | 8.5.65org.apache.tomcat:tomcat:8.5.65 |
Affected Products
tomcatapachedebian linuxdebiancommunications cloud native core policyoraclecommunications diameter signaling routeroraclecommunications pricing design centeroraclehospitality cruise shipboard property management systemoracleDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat:tomcat, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.apache.tomcat:tomcat to 10.0.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-30640 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.
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.
Red Hat OpenStack Platform's OpenDaylight will not be updated for this flaw because it was deprecated as of OpenStack Platform 14 and is only receiving security fixes for Critical flaws.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Fuse 7.11 | tomcat | RHSA-2022:5532 |
| Red Hat JBoss Web Server 5 | tomcat | RHSA-2021:4863 |
| Red Hat JBoss Web Server 5.6 on RHEL 7 | jws5-tomcat-0:9.0.50-3.redhat_00004.1.el7jws | RHSA-2021:4861 |
| Red Hat Support for Spring Boot 2.5.10 | tomcat | RHSA-2022:1179 |
Frequently Asked Questions
Is CVE-2021-30640 in your dependencies?
Find it across Maven, including transitive dependencies.