CVE-2019-11388 : Security Advisory and Response

A vulnerability has been found in OWASP ModSecurity Core Rule Set (CRS) up to version 3.1.0, allowing attackers to trigger a denial of service (ReDOS) attack. The software maintainer disputes this as a vulnerability.

Understanding CVE-2019-11388

This CVE involves a disputed vulnerability in OWASP ModSecurity Core Rule Set (CRS) up to version 3.1.0.

What is CVE-2019-11388?

The vulnerability allows attackers to exploit the file /rules/REQUEST-932-APPLICATION-ATTACK-RCE.conf to launch a denial of service (ReDOS) attack by inputting a specially crafted string with nested repetition operators.
The software maintainer disagrees with labeling this as a vulnerability, stating it cannot be exploited through ModSecurity.

The Impact of CVE-2019-11388

Attackers can potentially disrupt services by triggering a denial of service attack.
The disputed nature of the vulnerability may lead to varying interpretations of its severity.

Technical Details of CVE-2019-11388

This section provides technical insights into the vulnerability.

Vulnerability Description

The vulnerability resides in the file /rules/REQUEST-932-APPLICATION-ATTACK-RCE.conf within OWASP ModSecurity CRS.
It allows remote attackers to execute a ReDOS attack by using a specifically crafted string with nested repetition operators.

Affected Systems and Versions

OWASP ModSecurity Core Rule Set (CRS) up to version 3.1.0 is affected by this vulnerability.

Exploitation Mechanism

Attackers exploit the vulnerability by inputting a malicious string with nested repetition operators into the specified file.

Mitigation and Prevention

Protecting systems from CVE-2019-11388 requires immediate actions and long-term security practices.

Immediate Steps to Take

Monitor and restrict access to the vulnerable file /rules/REQUEST-932-APPLICATION-ATTACK-RCE.conf.
Consider alternative security measures to mitigate the risk of ReDOS attacks.

Long-Term Security Practices

Regularly update and patch OWASP ModSecurity CRS to address security vulnerabilities.
Implement robust security protocols to prevent and detect denial of service attacks.
Stay informed about security advisories and best practices in web application security.
Conduct regular security assessments to identify and address potential vulnerabilities.

Patching and Updates

Stay informed about patches and updates released by OWASP ModSecurity CRS to address this vulnerability.