CVE-2016-3081
HIGHCVE-2016-3081 is a high-severity (CVSS 8.1) CWE-77 vulnerability in org.apache.struts:struts2-core. 3 public exploit references exist, so weaponization risk is real. O3 Security confirms whether CVE-2016-3081 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Apache Struts RCE Vulnerability
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.
How urgent is this, really
CVE-2016-3081 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE sits: patch-first territory.
Where this sits among everything scored
Of 368,770 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.apache.struts:struts2-core☕org.apache.struts:struts2-core☕org.apache.struts:struts2-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
Apache Struts 2.3.19 to 2.3.20.2, 2.3.21 to 2.3.24.1, and 2.3.25 to 2.3.28, when Dynamic Method Invocation is enabled, allow remote attackers to execute arbitrary code via method: prefix, related to chained expressions.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.struts:struts2-core | ≥ 2.3.19&&< 2.3.20.3 | 2.3.20.3 |
| ☕Maven | org.apache.struts:struts2-core | ≥ 2.3.21&&< 2.3.24.3 | 2.3.24.3 |
| ☕Maven | org.apache.struts:struts2-core | ≥ 2.3.25&&< 2.3.28.1 | 2.3.28.1 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Apache Struts - Dynamic Method Invocation Remote Code Execution (Metasploit)
by Metasploit · May 2, 2016
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.struts:struts2-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.struts:struts2-core to 2.3.20.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-3081 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-2016-3081 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-2016-3081. 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-2016-3081 in your dependencies?
O3 detects CVE-2016-3081 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.