CVE-2019-16516
There is a user enumeration vulnerability, allowing an unauthenticated attacker to determine with certainty if an account exists for a given username.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 19.1%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.
Description
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.
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- EPSS
- 19.10% probability · 97th percentile
- Public exploits
- 1 in Exploit-DB · first 5 January 2022
- CISA KEV
- Not listed
- Weakness
- CWE-203
- Affected
- connectwise/control
- Source
- cve@mitre.org
EPSS 19.1% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
Public exploits (1)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- http://packetstormsecurity.com/files/165432/ConnectWise-Control-19.2.24707-Username-Enumeration.htmlExploit, Third Party Advisory, VDB Entry
- https://blog.huntresslabs.com/validating-the-bishop-fox-findings-in-connectwise-control-9155eec36a34Exploit, Third Party Advisory
- https://know.bishopfox.com/advisoriesThird Party Advisory
- https://know.bishopfox.com/advisories/connectwise-controlExploit, Third Party Advisory
- https://www.crn.com/news/managed-services/connectwise-control-msp-security-vulnerabilities-are-severe-bishop-foxThird Party Advisory
- https://www.crn.com/slide-shows/managed-services/connectwise-control-attack-chain-exploit-20-questions-for-security-researcher-bishop-foxThird Party Advisory
- http://packetstormsecurity.com/files/165432/ConnectWise-Control-19.2.24707-Username-Enumeration.htmlExploit, Third Party Advisory, VDB Entry
- https://blog.huntresslabs.com/validating-the-bishop-fox-findings-in-connectwise-control-9155eec36a34Exploit, Third Party Advisory
- https://know.bishopfox.com/advisoriesThird Party Advisory
- https://know.bishopfox.com/advisories/connectwise-controlExploit, Third Party Advisory
- https://www.crn.com/news/managed-services/connectwise-control-msp-security-vulnerabilities-are-severe-bishop-foxThird Party Advisory
- https://www.crn.com/slide-shows/managed-services/connectwise-control-attack-chain-exploit-20-questions-for-security-researcher-bishop-foxThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.