SentinelOne discovered a denial of service (DoS) vulnerability in Cobalt Strike. The bug (aka Hotcobalt) can cause a denial of service on a teamserver by using a fake beacon sending abnormally large screenshots.

This bug has been fixed in Cobalt Strike 4.4

Consider mitigating this risk to a teamserver by hardening your C2 infrastructure.

  • Update to Cobalt Strike 4.4
  • Disable staging on versions of Cobalt Strike prior to 4.4
  • Limit access to your teamserver infrastructure to only trusted sources

Thank you, SentinelOne working with us and responsibly disclosing this bug.

References:

  • https://labs.sentinelone.com/hotcobalt-new-cobalt-strike-dos-vulnerability-that-lets-you-halt-operations/