CVE-2017-11142 : Vulnerability Insights and Analysis

PHP versions prior to 5.6.31, 7.x before 7.0.17, and 7.1.x before 7.1.3 are vulnerable to a denial of service attack through CPU consumption by injecting lengthy form variables.

Understanding CVE-2017-11142

What is CVE-2017-11142?

In PHP versions before 5.6.31, 7.x before 7.0.17, and 7.1.x before 7.1.3, a vulnerability exists that allows remote attackers to trigger a denial of service attack by injecting long form variables.

The Impact of CVE-2017-11142

This vulnerability can be exploited to cause a denial of service by consuming excessive CPU resources, potentially leading to system unresponsiveness.

Technical Details of CVE-2017-11142

Vulnerability Description

The vulnerability in PHP versions allows attackers to perform a denial of service attack by injecting lengthy form variables directly connected to main/php_variables.c.

Affected Systems and Versions

PHP versions prior to 5.6.31
PHP 7.x before 7.0.17
PHP 7.1.x before 7.1.3

Exploitation Mechanism

Attackers can exploit this vulnerability by injecting long form variables, which are linked to main/php_variables.c, causing CPU consumption and leading to a denial of service.

Mitigation and Prevention

Immediate Steps to Take

Update PHP to versions 5.6.31, 7.0.17, or 7.1.3 or later to mitigate the vulnerability.
Monitor system resources for unusual CPU consumption that could indicate an ongoing attack.

Long-Term Security Practices

Regularly update PHP and other software to the latest versions to patch known vulnerabilities.
Implement input validation to prevent malicious input from being processed.
Employ network and application firewalls to filter and monitor incoming traffic.

Patching and Updates

Apply patches provided by PHP to address the vulnerability and prevent exploitation.