CVE-2020-7065 : What You Need to Know

PHP versions 7.3.x below 7.3.16 and 7.4.x below 7.4.4 are vulnerable to a stack-buffer-overflow issue when using the mb_strtolower() function with UTF-32LE encoding.

Understanding CVE-2020-7065

In PHP versions 7.3.x below 7.3.16 and 7.4.x below 7.4.4, a specific function call could lead to memory corruption, crashes, and potentially code execution.

What is CVE-2020-7065?

This CVE identifies a vulnerability in PHP versions 7.3.x and 7.4.x that allows attackers to trigger a stack-based buffer overflow by utilizing the mb_strtolower() function with UTF-32LE encoding.

The Impact of CVE-2020-7065

The vulnerability could result in memory corruption, system crashes, and potentially enable malicious actors to execute arbitrary code on the affected system.

Technical Details of CVE-2020-7065

PHP versions 7.3.x and 7.4.x are susceptible to a stack-based buffer overflow when certain conditions are met.

Vulnerability Description

When utilizing the mb_strtolower() function with UTF-32LE encoding, invalid strings can cause PHP to overwrite a stack-allocated buffer, leading to memory corruption and potential code execution.

Affected Systems and Versions

Product: PHP
Vendor: PHP Group
Versions Affected: 7.3.x (less than 7.3.16), 7.4.x (less than 7.4.4)

Exploitation Mechanism

The vulnerability arises when utilizing the mb_strtolower() function with specific encoding, allowing attackers to manipulate strings and trigger the buffer overflow.

Mitigation and Prevention

It is crucial to take immediate steps to address and prevent exploitation of CVE-2020-7065.

Immediate Steps to Take

Update PHP to versions 7.3.16 and 7.4.4 or later to mitigate the vulnerability.
Monitor for any unusual system behavior that could indicate exploitation.

Long-Term Security Practices

Regularly update PHP and other software to patch known vulnerabilities.
Implement code reviews and security testing to identify and address potential issues.

Patching and Updates

Apply patches provided by PHP Group promptly to address the stack-buffer-overflow vulnerability.