CVE-2021-29476: 
PHP vulnerability analysis and mitigation

Requests, a PHP HTTP library, was found to have a critical vulnerability (CVE-2021-29476) related to insecure deserialization in FilteredIterator. The vulnerability affects Requests versions 1.6.0, 1.6.1, and 1.7.0. This security issue was discovered and disclosed on April 27, 2021, with a CVSS v3.1 base score of 9.8 (Critical) (GitHub Advisory).

The vulnerability (CWE-502) involves the mishandling of deserialization in FilteredIterator component, which could lead to PHP Object Injection. The vulnerability has received a Critical severity rating with a CVSS v3.1 base score of 9.8, characterized by network attack vector, low attack complexity, no privileges required, and no user interaction needed. The vulnerability affects all security aspects with high impact on confidentiality, integrity, and availability (NVD).

The vulnerability can result in a total loss of confidentiality, integrity, and availability of the affected system. An attacker can potentially execute arbitrary code, access sensitive information, or cause system disruption through the exploitation of this deserialization vulnerability (Snyk).

Users of Requests versions 1.6.0, 1.6.1, and 1.7.0 should update to version 1.8.0 or higher, which contains the security patch. The fix involves disabling deserialization in the FilteredIterator component (GitHub PR).