CVE ID: CVE-2024-22903

Title: Command Injection Vulnerability in SystemHandler.class.php of Vinchin Backup & Recovery Versions 7.2 and Earlier

Description:
A significant security vulnerability, CVE-2024-22903, has been identified in the `deleteUpdateAPK` function within the `SystemHandler.class.php` file of Vinchin Backup & Recovery software, affecting versions 7.2 and earlier. This function, designed to delete APK files, is prone to a command injection vulnerability due to improper handling of input parameters.

Function Analysis:
- The function extracts `md5` and `file_name` parameters from user input.
- It includes a check for an empty `file_name`, but lacks adequate validation or sanitization for the input used in constructing system commands.
- The command to delete the specified APK file, built using the `file_name` parameter, is executed via the `exec` function, leading to a security vulnerability.

Exploitation Risk:
Attackers can exploit this flaw by inserting malicious commands in the `file_name` parameter. When this parameter is processed by the vulnerable function, the injected commands are executed on the server, presenting a severe risk of unauthorized access or control.

Current Status:
As of the latest information, there is no known patch available for this vulnerability in versions 7.2 and earlier of Vinchin Backup & Recovery.

Recommendation:
Users are urged to be vigilant and to monitor Vinchin for any security updates. Until a patch is released, implementing additional security controls and closely monitoring system activity is crucial for mitigating the risk posed by this vulnerability.

Signed,Valentin Lobstein