An issue was discovered in ConnectWise Control (formerly known as ScreenConnect) 19.3.25270.7185. There is a user enumeration vulnerability, allowing an unauthenticated attacker to determine with certainty if an account exists for a given username.

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-16516
• https://blog.huntresslabs.com/validating-the-bishop-fox-findings-in-connectwise-control-9155eec36a34
• https://know.bishopfox.com/advisories
• https://know.bishopfox.com/advisories/connectwise-control
• 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
• http://packetstormsecurity.com/files/165432/ConnectWise-Control-19.2.24707-Username-Enumeration.html