ConnectWise ScreenConnect Authentication Bypass
CVE-2024-1709 is a critical-severity authentication bypass using an alternate path or channel vulnerability in ScreenConnect from ConnectWise, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected ScreenConnect versions: 23.9.7 and earlier. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on February 22, 2024, which means attacks have been observed in the wild, including in ransomware campaigns.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Check which version of ScreenConnect you run against the affected versions below, and install the vendor's latest release.
- CISA's required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- Read the advisory on connectwise.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| ConnectWise | ScreenConnect | 23.9.7 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 10.0 | Critical | CNA |
| CVSS 3.1 | 10.0 | Critical | NVD |
Official description
ConnectWise ScreenConnect 23.9.7 and prior are affected by an Authentication Bypass Using an Alternate Path or Channel vulnerability, which may allow an attacker direct access to confidential information or critical systems.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Authentication Bypass Using an Alternate Path or Channel
The product requires authentication, but the product has an alternate path or channel that does not require authentication.
How developers prevent this class of flaw
- Funnel all access through a single choke point to simplify how users can access a resource. For every access, perform a check to determine if the user has permissions to access the resource.
More Authentication Bypass Using an Alternate Path or Channel vulnerabilities (CWE-288)
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/rapid7/metasploit-framework/pull/18870Issue Tracking, Third Party Advisory
Third-party and government advisories
- techcrunch.com/2024/02/21/researchers-warn-high-risk-connectwise-flaw-under-attack-is-embarrassingly-easy-to-…Press/Media Coverage, Third Party Advisory
- bleepingcomputer.com/news/security/connectwise-urges-screenconnect-admins-to-patch-critical-rce-flaw/Press/Media Coverage, Third Party Advisory
- horizon3.ai/attack-research/red-team/connectwise-screenconnect-auth-bypass-deep-dive/Third Party Advisory
- huntress.com/blog/vulnerability-reproduced-immediately-patch-screenconnect-23-9-8Third Party Advisory
- securityweek.com/connectwise-confirms-screenconnect-flaw-under-active-exploitation/Press/Media Coverage, Third Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-1709US Government Resource
Technical write-ups (may include proof of concept)
- github.com/watchtowrlabs/connectwise-screenconnect_auth-bypass-add-user-pocExploit, Third Party Advisory
- huntress.com/blog/a-catastrophe-for-control-understanding-the-screenconnect-authentication-bypassExploit, Third Party Advisory
- huntress.com/blog/detection-guidance-for-connectwise-cwe-288-2Exploit, Third Party Advisory
Other vulnerabilities in ScreenConnect
- 9.9 Critical severity
- 9.0 Critical severity
- 9.1 Critical severity
- 7.2 High severity
- 8.4 High severity
ConnectWise ScreenConnect Path Traversal Exploited
Recent Authentication Bypass Using an Alternate Path or Channel vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 8.0 High severity
- 9.1 Critical severity
- 9.8 Critical severity
Spotted an error? Tell us.