CVE-2019-9020 : What You Need to Know

A vulnerability was found in PHP versions prior to 5.6.40, 7.x before 7.1.26, 7.2.x before 7.2.14, and 7.3.x before 7.3.1. Incorrect input to xmlrpc_decode() function can lead to unauthorized memory access, potentially resulting in memory read beyond allocated heap or accessing already freed memory.

Understanding CVE-2019-9020

This CVE identifies a vulnerability in PHP versions that could allow unauthorized memory access.

What is CVE-2019-9020?

This CVE pertains to a vulnerability in PHP versions prior to 5.6.40, 7.x before 7.1.26, 7.2.x before 7.2.14, and 7.3.x before 7.3.1. By providing incorrect input to the xmlrpc_decode() function, attackers could exploit this issue to gain unauthorized access to memory.

The Impact of CVE-2019-9020

The vulnerability could lead to unauthorized access to memory, potentially allowing attackers to read beyond the bounds of allocated heap or access memory that has already been freed. This could result in security breaches and unauthorized data access.

Technical Details of CVE-2019-9020

This section provides technical details about the vulnerability.

Vulnerability Description

The vulnerability is associated with the xml_elem_parse_buf function in ext/xmlrpc/libxmlrpc/xml_element.c. Invalid input to the xmlrpc_decode() function can trigger an invalid memory access, such as a heap out-of-bounds read or read-after-free scenario.

Affected Systems and Versions

PHP versions prior to 5.6.40
PHP 7.x before 7.1.26
PHP 7.2.x before 7.2.14
PHP 7.3.x before 7.3.1

Exploitation Mechanism

Attackers can exploit this vulnerability by providing incorrect input to the xmlrpc_decode() function, leading to unauthorized memory access and potential security breaches.

Mitigation and Prevention

Protecting systems from CVE-2019-9020 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update PHP to versions 5.6.40, 7.1.26, 7.2.14, or 7.3.1 to mitigate the vulnerability.
Monitor for any unauthorized memory access or unusual activities on the system.

Long-Term Security Practices

Regularly update PHP and other software to the latest versions to patch known vulnerabilities.
Implement secure coding practices to prevent invalid input vulnerabilities.

Patching and Updates

Apply patches provided by PHP to address the vulnerability.
Stay informed about security advisories and updates from PHP and relevant vendors.