What happened
Yonyou U8 CRM contains an unauthenticated SQL injection vulnerability in the fillbacksettingedit.php configuration endpoint where the DontCheckLogin=1 parameter bypasses authentication and the id parameter is incorporated into SQL queries without sanitization. Attackers can exploit this flaw to execute arbitrary SQL commands and, on Microsoft SQL Server deployments with xp_cmdshell enabled, write backdoor files and execute arbitrary operating system commands. Exploitation evidence was first observed by the Shadowserver Foundation on 2025-02-13.
Affected versions
U8 CRM: 18 (custom); 16.5 (custom); 16.1 (custom); 16.0 (custom); 15.1 (custom); 13 (custom) Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.