CVE-2020-29553: 
PHP vulnerability analysis and mitigation

The vulnerability (CVE-2020-29553) affects the Scheduler component in Grav CMS through version 1.7.0-rc.17. This security flaw was discovered and recorded on December 4, 2020, and allows an attacker to execute system commands by tricking an administrator into visiting a malicious website through a Cross-Site Request Forgery (CSRF) attack (MITRE CVE).

The vulnerability has been assigned a CVSS v3.1 base score of 8.8 (HIGH) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. It is classified as CWE-352 (Cross-Site Request Forgery) and requires user interaction for successful exploitation. The CVSS v2.0 score is 5.1 (MEDIUM) with the vector (AV:N/AC:H/Au:N/C:P/I:P/A:P) (NVD).

If successfully exploited, this vulnerability allows attackers to execute system commands with the privileges of the admin user who visits the malicious website. This could lead to complete system compromise, including potential data theft, system manipulation, and service disruption (NVD).

The vulnerability requires user interaction, specifically requiring an administrator to visit a malicious website. The attack can be executed remotely, and no authentication is required to launch the attack, though it does require the target to be an authenticated administrator (NVD).

Affected users should upgrade their Grav CMS installations to a version newer than 1.7.0-rc.17. The vulnerability affects all versions up to and including 1.6.31 and all 1.7.0 beta and release candidate versions through rc.17 (NVD).