Almost 10% of all internet-accessible SugarCRM servers (representing 291 of 3,066 servers, based on Censys data) were hacked and compromised using a zero-day exploit published online in late December.
SugarCRM describes the zero-day as an authentication bypass that allows threat actors to upload encoded images containing malicious PHP code on SugarCRM platforms.
Censys researchers say the final payload in many attacks appears to be a simple web shell that could be used to control compromised systems. According to an open-source report, the zero-day appears to have been used to drop crypto-mining malware as well.
SugarCRM released an official patch a week after public disclosure. The company said that all users who run on-premise servers of its SugarCRM Sell, Serve, Enterprise, Professional, and Ultimate services should apply the update to avoid future attacks.
The company says it has hired a forensics firm to investigate the one-week time window during which its cloud platform was exposed to possible attacks.
No CVE has been assigned to this issue yet.