CVE-2019-11391

Name: CVE-2019-11391
Creator: NVD / NIST
Published: 2019-04-21T02:29:00.487+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 1.63%

Last modified Jun 17, 2026

CVE-2019-11391 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. An issue was discovered in OWASP ModSecurity Core Rule Set (CRS) through 3.1.0. /rules/REQUEST-933-APPLICATION-ATTACK-PHP.conf allows remote attackers to cause a denial of service (ReDOS) by entering a specially crafted string with $a# at the beginning and nested repetition operators. EPSS estimates a 1.63% chance of exploitation in the next 30 days.

Description

An issue was discovered in OWASP ModSecurity Core Rule Set (CRS) through 3.1.0. /rules/REQUEST-933-APPLICATION-ATTACK-PHP.conf allows remote attackers to cause a denial of service (ReDOS) by entering a specially crafted string with $a# at the beginning and nested repetition operators. NOTE: the software maintainer disputes that this is a vulnerability because the issue cannot be exploited via ModSecurity

Metrics

CVSS 3.1

5.3/10

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

EPSS Probability

1.63%

73.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-400

Affected Software

Vendor	Product	Versions
Modsecurity	Owasp Modsecurity Core Rule Set	<= 3.1.0

References

https://github.com/SpiderLabs/owasp-modsecurity-crs/issues/1357Issue Tracking, Third Party Advisory
https://github.com/SpiderLabs/owasp-modsecurity-crs/issues/1372Exploit, Issue Tracking, Third Party Advisory
https://github.com/SpiderLabs/owasp-modsecurity-crs/issues/1357Issue Tracking, Third Party Advisory
https://github.com/SpiderLabs/owasp-modsecurity-crs/issues/1372Exploit, Issue Tracking, Third Party Advisory

Timeline

Published: Apr 21, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-11391?

How severe is CVE-2019-11391?

CVE-2019-11391 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 1.63% probability of exploitation in the next 30 days.

How do I fix CVE-2019-11391?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-11391?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST