CVE-2021-24122
MEDIUMCVE-2021-24122 is a medium-severity (CVSS 5.9) Information Exposure vulnerability in org.apache.tomcat.embed:tomcat-embed-core. O3 Security confirms whether CVE-2021-24122 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Information Disclosure in Apache Tomcat
Real-World Exposure
org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-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
When serving resources from a network location using the NTFS file system, Apache Tomcat versions 10.0.0-M1 to 10.0.0-M9, 9.0.0.M1 to 9.0.39, 8.5.0 to 8.5.59 and 7.0.0 to 7.0.106 were susceptible to JSP source code disclosure in some configurations. The root cause was the unexpected behaviour of the JRE API File.getCanonicalPath() which in turn was caused by the inconsistent behaviour of the Windows API (FindFirstFileW) in some circumstances.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 10.0.0-M1&&< 10.0.0-M10 | 10.0.0-M10 |
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 9.0.0&&< 9.0.40 | 9.0.40 |
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 8.5.0&&< 8.5.60 | 8.5.60 |
| ☕Maven | org.apache.tomcat.embed:tomcat-embed-core | ≥ 7.0.0&&< 7.0.107 | 7.0.107 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat.embed:tomcat-embed-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.apache.tomcat.embed:tomcat-embed-core to 10.0.0-M10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-24122 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-2021-24122 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-2021-24122. 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 Red Hat OpenStack Platform's OpenDaylight, tomcat is disabled by default. Further, ODL deployments are not supported on untrusted administrator networks; even if tomcat is enabled, if random users can access it, this would be in an unsupported configuration. For this reason, the RHOSP impact has been reduced and…
Frequently Asked Questions
Is CVE-2021-24122 in your dependencies?
O3 detects CVE-2021-24122 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.