CVE-2021-40690
HIGHCVE-2021-40690 is a high-severity (CVSS 7.5) Information Exposure vulnerability in org.apache.santuario:xmlsec. 2 public exploit references exist, so weaponization risk is real. O3 Security confirms whether CVE-2021-40690 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Exposure of Sensitive Information to an Unauthorized Actor in Apache Santuario
Blast Radius
org.apache.santuario:xmlsec☕org.apache.santuario:xmlsecReal-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
All versions of Apache Santuario - XML Security for Java prior to 2.2.3 and 2.1.7 are vulnerable to an issue where the "secureValidation" property is not passed correctly when creating a KeyInfo from a KeyInfoReference element. This allows an attacker to abuse an XPath Transform to extract any local .xml files in a RetrievalMethod element.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.santuario:xmlsec | ≥ 2.2.0&&< 2.2.3 | 2.2.3 |
| ☕Maven | org.apache.santuario:xmlsec | all versions | 2.1.7 |
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.apache.santuario:xmlsec. 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.santuario:xmlsec to 2.2.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-40690 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-2021-40690 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-2021-40690. 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-2021-40690 in your dependencies?
O3 detects CVE-2021-40690 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.