CVE-2021-36374
MEDIUMCVE-2021-36374 is a medium-severity (CVSS 5.5) vulnerability in org.apache.ant:ant. O3 Security confirms whether CVE-2021-36374 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Improper Handling of Length Parameter Inconsistency in Apache Ant
Real-World Exposure
org.apache.ant:ant☕org.apache.ant:antReal-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 reading a specially crafted ZIP archive, or a derived formats, an Apache Ant build can be made to allocate large amounts of memory that leads to an out of memory error, even for small inputs. This can be used to disrupt builds using Apache Ant. Commonly used derived formats from ZIP archives are for instance JAR files and many office files. Apache Ant prior to 1.9.16 and 1.10.11 were affected.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.ant:ant | ≥ 1.9.0&&< 1.9.16 | 1.9.16 |
| ☕Maven | org.apache.ant:ant | ≥ 1.10.0&&< 1.10.11 | 1.10.11 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.ant:ant. 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.ant:ant to 1.9.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-36374 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-2021-36374 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-2021-36374. 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-2021-36374 in your dependencies?
O3 detects CVE-2021-36374 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.