Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2017-9791

Apache Struts Remote Code Execution

Apache Struts · 2.1.x series

Watch CVE-2017-9791 Browse KEV feed
Severity
CVSS 9.8 · Critical
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
98.9%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2017-9791 is an unauthenticated vulnerability affecting Apache Struts. The Struts 1 plugin in 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...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

Apache Struts 2.1.x series.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Apache Struts Remote Code Execution

The Struts 1 plugin in 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.

Apache Software Foundation Affected
Apache Struts
2.1.x series 2.3.x series
Published
10 Jul 2017
Exploitation Reported
10 Feb 2022
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

apache nuclei_scanner metasploit cisa

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 10 Feb 2022

A trusted third party reported exploitation.

Proof of concept available

GitHub

Recorded 23 Sep 2017

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

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Source Added
CISA First 2022-02-10 00:00 UTC
The Shadowserver 2026-09-18 00:00 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Metasploit https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/http/struts2_code_exec_showcase.rb 28 Apr 2025
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2017/CVE-2017-9791.yaml 25 Apr 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

9.8 Critical

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

98.9%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Input Validation CWE-20

All CVSS Scores

CVSS v3.1 9.8 Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v2.0 7.5 High

AV:N/AC:L/Au:N/C:P/I:P/A:P

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

Apache Struts2 S2-053 - Remote Code Execution

nuclei · Created Unknown

struts2_code_exec_showcase

metasploit · Created Unknown

Metasploit module for CVE-2017-9791

Timeline

From disclosure to observed exploitation

  1. 00:00 UTC

    KEV confirmed by The Shadowserver

    Exploitation attested by an external source

  2. 15:02 UTC

    Metasploit module available

    Exploit module available

  3. 15:02 UTC

    Public PoC available

    Public proof-of-concept code published

  4. 00:00 UTC

    Nuclei template available

    Scanner coverage available

  5. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  6. 16:00 UTC

    CVE published

    Vulnerability disclosed publicly

  7. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2017-9791

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2017-9791",
  "confidence": "Confirmed",
  "cvss_score": 9.8,
  "cvss_estimated": false,
  "epss_score": 0.98908,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}