CVE-2019-9022 : Vulnerability Insights and Analysis

A vulnerability has been found in PHP versions 7.x prior to 7.1.26, 7.2.x before 7.2.14, and 7.3.x before 7.3.2, allowing a malicious DNS server to manipulate PHP's use of memcpy, resulting in read operations exceeding the allocated buffer for DNS data.

Understanding CVE-2019-9022

This CVE involves a vulnerability in PHP versions 7.x, 7.1.x, 7.2.x, and 7.3.x that can be exploited by a hostile DNS server.

What is CVE-2019-9022?

The issue arises from dns_get_record misinterpreting a DNS response
Exploitation can lead to read operations surpassing the allocated buffer for DNS data
Specifically impacts php_parserr in ext/standard/dns.c for DNS_CAA and DNS_ANY queries

The Impact of CVE-2019-9022

Allows a malicious DNS server to manipulate PHP's memcpy usage
Can result in unauthorized read operations beyond the DNS data buffer

Technical Details of CVE-2019-9022

This section provides more in-depth technical insights into the CVE.

Vulnerability Description

PHP versions 7.x, 7.1.x, 7.2.x, and 7.3.x are affected
Vulnerability in dns_get_record misinterpreting DNS responses

Affected Systems and Versions

PHP versions 7.x, 7.1.x, 7.2.x, and 7.3.x

Exploitation Mechanism

Malicious DNS server manipulates PHP's memcpy usage
Read operations exceed allocated buffer for DNS data

Mitigation and Prevention

Protecting systems from CVE-2019-9022 is crucial to ensure security.

Immediate Steps to Take

Update PHP to versions 7.1.26, 7.2.14, or 7.3.2
Monitor DNS responses for any anomalies

Long-Term Security Practices

Regularly update PHP and other software components
Implement DNS security best practices

Patching and Updates

Apply patches provided by PHP for the affected versions