CVE-2020-7062: 
PHP vulnerability analysis and mitigation

CVE-2020-7062 is a vulnerability discovered in PHP versions 7.2.x below 7.2.28, 7.3.x below 7.3.15 and 7.4.x below 7.4.3. The vulnerability occurs when using file upload functionality with upload progress tracking enabled but session.upload_progress.cleanup is set to 0 (disabled). When a file upload fails under these conditions, the upload procedure attempts to clean up non-existent data, leading to a null pointer dereference (Debian Tracker).

The vulnerability is triggered during the file upload process when specific conditions are met: upload progress tracking must be enabled, session.upload_progress.cleanup must be set to 0 (disabled), and the file upload must fail. Under these conditions, the upload procedure attempts to clean up data that does not exist, resulting in a null pointer dereference (NVD).

The primary impact of this vulnerability is a potential crash of the PHP application when the conditions are met. The null pointer dereference would likely lead to a denial of service condition (Ubuntu Security).

The vulnerability has been fixed in PHP versions 7.4.3, 7.3.15, and 7.2.28. Users should upgrade to these versions or later to address the issue. Various Linux distributions have also released security updates to address this vulnerability in their PHP packages (Red Hat Portal).