CVE-2020-7059 : Exploit Details and Defense Strategies
Learn about CVE-2020-7059 affecting PHP versions 7.2.x, 7.3.x, and 7.4.x. Understand the out-of-bounds read vulnerability in the fgetss() function, its impact, and mitigation steps.
PHP versions 7.2.x, 7.3.x, and 7.4.x are affected by an out-of-bounds read vulnerability when using the fgetss() function. This could lead to information disclosure or crashes.
Understanding CVE-2020-7059
This CVE involves a vulnerability in PHP versions 7.2.x, 7.3.x, and 7.4.x that allows attackers to read past the allocated buffer when using the fgetss() function.
What is CVE-2020-7059?
When utilizing the fgetss() function to read data with stripping tags, PHP versions 7.2.x below 7.2.27, 7.3.x below 7.3.14, and 7.4.x below 7.4.2 may allow the supply of data that causes the function to read beyond the allocated buffer, potentially resulting in information disclosure or system crashes.
The Impact of CVE-2020-7059
The vulnerability poses a medium severity risk with a CVSS base score of 6.5. It has a low attack complexity and requires no privileges, but could lead to information disclosure or system crashes.
Technical Details of CVE-2020-7059
PHP versions 7.2.x, 7.3.x, and 7.4.x are affected by this vulnerability.
Vulnerability Description
The issue arises when using the fgetss() function to read data, allowing attackers to read beyond the allocated buffer.
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 data that causes the fgetss() function to read past the allocated buffer.
Mitigation and Prevention
To address CVE-2020-7059, consider the following steps:
Immediate Steps to Take
- Avoid using the fgetss() function, which has been deprecated as of PHP 7.3.0
- Use alternative functions like strip_tags() for sanitizing HTML code
Long-Term Security Practices
- Regularly update PHP to the latest version to patch known vulnerabilities
- Implement secure coding practices to prevent buffer overflows and other common vulnerabilities
Patching and Updates
Ensure that PHP is updated to versions 7.2.27, 7.3.14, or 7.4.2 to mitigate the risk of this vulnerability.