Fortinet says that an unknown threat actor exploited a critical flaw in its FortiOS SSL-VPN to infect systems at government and government-related organizations. Fortinet released a fix for the heap-based buffer overflow vulnerability (CVE-2022-42475) late last year. FortiOS SSL-VPN version 7.2.8 was released at the end of November; Fortinet published an advisory on December 12. In a January 11 blog post, Fortinet “details [their] initial investigation into this malware and additional IoCs identified during … ongoing analysis.”
Note
- Hard to find actual data, but successful exploits against VPNs seem to happen disproportionately at US government agencies. Some is likely that they are targeted more, but OIG reports often point out poor patching performance on obvious targets like VPNs with published vulnerabilities.
- Make sure you’re incorporating all the IOCs in your threat hunting, and verify you’ve updated your Fortinet SSL-VPN’s to the fixed FortiOS. The threat actor is working very hard to avoid detection, manipulating log files, shutting down logging and IPS services. The only workaround is disabling the SSL-VPN, which is likely unrealistic, even with all-hands on-deck. (no telecommuting.)
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