CVE-2020-7061 Explained : Impact and Mitigation

In PHP versions 7.3.x below 7.3.15 and 7.4.x below 7.4.3, a heap-buffer-overflow vulnerability exists in the phar_extract_file function on Windows systems.

Understanding CVE-2020-7061

This CVE involves a specific vulnerability in PHP versions that could potentially lead to information disclosure or system crashes.

What is CVE-2020-7061?

In PHP versions 7.3.x below 7.3.15 and 7.4.x below 7.4.3, a heap-buffer-overflow vulnerability occurs while extracting PHAR files on Windows using the phar extension. This vulnerability could result in a one-byte read past the allocated buffer, leading to potential information exposure or system instability.

The Impact of CVE-2020-7061

The vulnerability could allow an attacker to trigger a heap-buffer-overflow condition, potentially leading to information disclosure or system crashes.

Technical Details of CVE-2020-7061

This section provides more in-depth technical details about the CVE.

Vulnerability Description

The vulnerability arises from a heap-buffer-overflow issue in the phar_extract_file function in PHP versions 7.3.x and 7.4.x on Windows systems.

Affected Systems and Versions

Affected Platforms: Windows
Affected Product: PHP
Affected Versions:
PHP 7.3.x versions below 7.3.15
PHP 7.4.x versions below 7.4.3

Exploitation Mechanism

The vulnerability occurs when extracting PHAR files using the phar extension on Windows, allowing certain content within the PHAR file to exceed buffer limits, potentially leading to a heap-buffer-overflow condition.

Mitigation and Prevention

Protecting systems from CVE-2020-7061 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update PHP to versions 7.3.15 or 7.4.3 or later to mitigate the vulnerability.
Monitor vendor security advisories for patches and updates.

Long-Term Security Practices

Regularly update PHP and other software to the latest versions.
Implement secure coding practices to prevent buffer overflow vulnerabilities.

Patching and Updates

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