Description
An issue was discovered in ConnectWise Control (formerly known as ScreenConnect) 19.3.25270.7185. There is a CORS misconfiguration, which reflected the Origin provided by incoming requests. This allowed JavaScript running on any domain to interact with the server APIs and perform administrative actions, without the victim's knowledge.
References
- https://know.bishopfox.com/advisories
- https://know.bishopfox.com/advisories/connectwise-control
- https://blog.huntresslabs.com/validating-the-bishop-fox-findings-in-connectwise-control-9155eec36a34
- https://www.crn.com/news/managed-services/connectwise-control-msp-security-vulnerabilities-are-severe-bishop-fox
- https://www.crn.com/slide-shows/managed-services/connectwise-control-attack-chain-exploit-20-questions-for-security-researcher-bishop-fox