CVE-2017-11144 : Exploit Details and Defense Strategies

PHP versions prior to 5.6.31, 7.x before 7.0.21, and 7.1.x before 7.1.7 encountered an issue with the openssl extension's PEM sealing code, leading to a potential PHP interpreter crash due to a verification failure in the OpenSSL sealing function.

Understanding CVE-2017-11144

This CVE describes a vulnerability in PHP versions that could result in a PHP interpreter crash.

What is CVE-2017-11144?

In PHP versions before 5.6.31, 7.x before 7.0.21, and 7.1.x before 7.1.7, a flaw in the openssl extension's PEM sealing code could cause the PHP interpreter to crash due to a failure to verify the return value of the OpenSSL sealing function.

The Impact of CVE-2017-11144

The vulnerability could potentially lead to a denial of service (DoS) situation where an attacker could crash the PHP interpreter, impacting the availability of PHP-based applications.

Technical Details of CVE-2017-11144

This section provides more technical insights into the vulnerability.

Vulnerability Description

The issue stemmed from a failure to verify the return value of the OpenSSL sealing function, resulting in a PHP interpreter crash.

Affected Systems and Versions

PHP versions prior to 5.6.31
PHP 7.x before 7.0.21
PHP 7.1.x before 7.1.7

Exploitation Mechanism

The vulnerability could be exploited by an attacker to craft malicious inputs that trigger the flawed openssl extension's PEM sealing code, leading to a crash of the PHP interpreter.

Mitigation and Prevention

Protecting systems from CVE-2017-11144 requires specific actions to mitigate the risk.

Immediate Steps to Take

Update PHP to versions 5.6.31, 7.0.21, or 7.1.7 or later to address the vulnerability.
Monitor official PHP security advisories for patches and updates.

Long-Term Security Practices

Regularly update PHP and its extensions to the latest versions to prevent known vulnerabilities.
Implement secure coding practices to minimize the impact of potential vulnerabilities.

Patching and Updates

Apply patches provided by PHP to fix the openssl extension's PEM sealing code issue.