CVE-2017-9791 is a critical-severity (CVSS 9.8) Improper Input Validation vulnerability in org.apache.struts:struts2-struts1-plugin. It is in CISA's Known Exploited Vulnerabilities catalog (added 2022-02-10) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
Code execution in Apache Struts 1 plugin
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2022-02-10. Federal agencies were required to remediate by 2022-08-10.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2017-9791.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2017-9791 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
org.apache.struts:struts2-struts1-pluginReal-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
The Struts 1 plugin used with Apache Struts 2.1.x and 2.3.x might allow remote code execution via a malicious field value passed in a raw message to the ActionMessage.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.struts:struts2-struts1-plugin | all versions | No fix |
Affected Products
strutsapacheResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Apache Struts 2 - Struts 1 Plugin Showcase OGNL Code Execution (Metasploit)
by Metasploit · May 17, 2018
Apache Struts 2.3.x Showcase - Remote Code Execution
by Vex Woo · Jul 7, 2017
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-struts1-plugin, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of org.apache.struts:struts2-struts1-plugin has shipped for CVE-2017-9791 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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 to detect CVE-2017-9791
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2017-9791 -u https://target- Template
- Apache Struts2 S2-053 - Remote Code Execution
- Severity
- critical
- Impact
- Remote code execution
- Remediation
- Apply the latest security patches or upgrade to a non-vulnerable version of Apache Struts2.
Template by ProjectDiscovery nuclei-templates (pikpikcu), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2017-9791 in your dependencies?
Find it across Maven, including transitive dependencies.