Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2019-11043

Underflow in PHP-FPM can lead to RCE

PHP · affected before 7.1.33

Watch CVE-2019-11043 Browse KEV feed
Severity
CVSS 8.7 · High
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
99.8%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2019-11043 is an unauthenticated Underflow in PHP-FPM can lead to RCE. In PHP versions 7.1.x below 7.1.33, 7.2.x below 7.2.24 and 7.3.x below 7.3.11 in certain configurations of FPM setup it is possible to cause...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV.

Who is affected?

PHP affected before 7.1.33.

What should we do?

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

Overview

Underflow in PHP-FPM can lead to RCE

In PHP versions 7.1.x below 7.1.33, 7.2.x below 7.2.24 and 7.3.x below 7.3.11 in certain configurations of FPM setup it is possible to cause FPM module to write past allocated buffers into the space reserved for FCGI protocol data, thus opening the possibility of remote code execution.

PHP Affected
PHP
Before 7.1.33 Before 7.2.24 Before 7.3.11
View vendor advisory (opens in new tab)
Published
28 Oct 2019
Exploitation Reported
25 Mar 2022
Attack vector
Remote
Complexity
High
Privileges
None
User interaction
None

Tags

php cisa malware metasploit ransomware nuclei_scanner

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 25 Mar 2022

A trusted third party reported exploitation.

Used in malware

CISA

Recorded 25 Mar 2022

Malware families have been linked to exploitation of this CVE.

Proof of concept available

GitHub

Recorded 23 Oct 2019

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 2022-03-25 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
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2019/CVE-2019-11043.yaml 26 Aug 2026
Metasploit https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/http/php_fpm_rce.rb 28 Apr 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

8.7 High

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

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

EPSS

99.8%

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

Weaknesses

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') CWE-120

Potential Proof of Concepts

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

php_fpm_rce

metasploit · Created Unknown

Metasploit module for CVE-2019-11043

PHP-FPM Path Info Buffer Underflow - Remote Code Execution

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. 04:30 UTC

    Nuclei template available

    Scanner coverage available

  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

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  5. 00:00 UTC

    First public exploitation report

    Exploit observed in malware

  6. 14:19 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-2019-11043

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2019-11043",
  "confidence": "Confirmed",
  "cvss_score": 8.7,
  "cvss_estimated": false,
  "epss_score": 0.9978,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}