CVE-2021-21704 : Exploit Details and Defense Strategies
Discover the impact and technical details of CVE-2021-21704 affecting PHP versions 7.3.x, 7.4.x, and 8.0.x. Learn about mitigation strategies and necessary updates to enhance system security.
A detailed article outlining the multiple vulnerabilities in the Firebird client extension affecting PHP versions 7.3.x, 7.4.x, and 8.0.x.
Understanding CVE-2021-21704
This CVE involves vulnerabilities in PHP versions that can be exploited through the Firebird PDO driver extension.
What is CVE-2021-21704?
In PHP versions 7.3.x below 7.3.29, 7.4.x below 7.4.21, and 8.0.x below 8.0.8, a malicious database server leveraging the Firebird PDO driver extension can trigger crashes in various database functions. This can lead to denial of service, memory corruption, or crashes due to incorrect parsing of response data.
The Impact of CVE-2021-21704
The vulnerabilities can result in system crashes, denial of service attacks, and potential memory corruption, posing a medium severity threat with a CVSS base score of 5.
Technical Details of CVE-2021-21704
The technical details include vulnerability descriptions, affected systems and versions, and the exploitation mechanism.
Vulnerability Description
The vulnerabilities involve out-of-bounds read and integer overflow or wraparound issues.
Affected Systems and Versions
PHP versions 7.3.x, 7.4.x, and 8.0.x are affected by these vulnerabilities when using the Firebird PDO driver extension.
Exploitation Mechanism
A malicious database server can exploit these vulnerabilities by returning invalid response data that is not correctly parsed by the driver, leading to crashes in database functions.
Mitigation and Prevention
Learn about the immediate steps to take and the long-term security practices to mitigate the risks associated with CVE-2021-21704.
Immediate Steps to Take
Update PHP to versions 7.3.29, 7.4.21, or 8.0.8 to patch the vulnerabilities.
Long-Term Security Practices
Regularly update PHP and its extensions, apply security best practices, and monitor for any potential threats.
Patching and Updates
Stay informed about security advisories and promptly apply patches released by PHP to address security vulnerabilities.