CVE-2019-11389 : Exploit Details and Defense Strategies

A vulnerability was found in OWASP ModSecurity Core Rule Set (CRS) version 3.1.0 that allows attackers to launch a denial of service (ReDOS) attack by inputting a specifically crafted string. The software maintainer disputes the claim that this vulnerability can be exploited through ModSecurity.

Understanding CVE-2019-11389

This CVE involves a vulnerability in the OWASP ModSecurity Core Rule Set (CRS) version 3.1.0 that can be exploited for a denial of service attack.

What is CVE-2019-11389?

The vulnerability in the /rules/REQUEST-933-APPLICATION-ATTACK-PHP.conf file of OWASP ModSecurity CRS version 3.1.0 allows attackers to execute a ReDoS attack by using a specially crafted string.

The Impact of CVE-2019-11389

Attackers can exploit this vulnerability to launch denial of service attacks.
The issue can lead to service disruption and potential system unavailability.

Technical Details of CVE-2019-11389

This section provides technical insights into the vulnerability.

Vulnerability Description

The vulnerability exists in the /rules/REQUEST-933-APPLICATION-ATTACK-PHP.conf file of OWASP ModSecurity CRS version 3.1.0.
It enables attackers to perform a ReDoS attack by inputting a crafted string.

Affected Systems and Versions

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

Exploitation Mechanism

Attackers can exploit the vulnerability by inputting a specifically crafted string with certain characteristics.

Mitigation and Prevention

Protecting systems from CVE-2019-11389 requires immediate actions and long-term security practices.

Immediate Steps to Take

Monitor and restrict input data to prevent malicious strings.
Regularly update security patches and configurations.

Long-Term Security Practices

Implement input validation mechanisms to filter out potentially harmful strings.
Conduct regular security audits and penetration testing to identify vulnerabilities.

Patching and Updates

Apply patches and updates provided by OWASP ModSecurity to address the vulnerability.