CVE-2020-7060 : What You Need to Know

PHP versions 7.2.x, 7.3.x, and 7.4.x are affected by a global buffer-overflow vulnerability in the mbfl_filt_conv_big5_wchar function.

Understanding CVE-2020-7060

This CVE involves a vulnerability in PHP versions 7.2.x, 7.3.x, and 7.4.x that could allow an attacker to trigger a buffer overflow.

What is CVE-2020-7060?

When certain mbstring functions are used to convert multibyte encodings in PHP versions 7.2.x below 7.2.27, 7.3.x below 7.3.14, and 7.4.x below 7.4.2, it may lead to a buffer overflow in the mbfl_filt_conv_big5_wchar function, potentially resulting in information disclosure or a crash.

The Impact of CVE-2020-7060

The vulnerability has a CVSS base score of 6.5, indicating a medium severity issue. The impact includes the potential for information disclosure or system crashes.

Technical Details of CVE-2020-7060

PHP versions 7.2.x, 7.3.x, and 7.4.x are affected by this vulnerability.

Vulnerability Description

The issue allows attackers to supply data that can cause the mbfl_filt_conv_big5_wchar function to read past the allocated buffer, leading to a buffer overflow.

Affected Systems and Versions

PHP 7.2.x versions below 7.2.27
PHP 7.3.x versions below 7.3.14
PHP 7.4.x versions below 7.4.2

Exploitation Mechanism

Attackers can exploit this vulnerability by supplying specific data to trigger the buffer overflow in the mbfl_filt_conv_big5_wchar function.

Mitigation and Prevention

It is crucial to take immediate steps to address and prevent the exploitation of this vulnerability.

Immediate Steps to Take

Update PHP to versions 7.2.27, 7.3.14, or 7.4.2, which contain fixes for this vulnerability.
Monitor for any unusual activities that could indicate exploitation of the vulnerability.

Long-Term Security Practices

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

Patching and Updates

Apply the security updates provided by PHP Group to address CVE-2020-7060 and other potential vulnerabilities.