Assessment
Why it matters
CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 100.0%; technical severity is CVSS 9.8.
This vulnerability allows remote attackers to bypass authentication on affected installations of PaperCut NG 22.0.5 (Build 63914). Authentication is not required to exploit this vulnerability. The specific flaw exists within the SetupCompleted class. The issue results from improper access control. An attacker can leverage this vulnerability to bypass authentication and execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-18987.
Who should care
- Teams operating MF/NG, Papercut Mf, Papercut Ng
- Vulnerability and exposure management teams
- Security operations teams monitoring exploitation activity
Response plan
What I would do
- Confirm whether MF/NG, Papercut Mf, Papercut Ng is present in the environment.
- Identify affected versions and establish whether vulnerable services are exposed or reachable.
- Apply updates per vendor instructions.
- Review relevant security telemetry for evidence of attempted or successful exploitation.
- Document the remediation decision and track it to verified completion.
Vendor remediation
Patch and remediation links
Use the vendor source below to confirm the correct fixed version, package or mitigation for your affected product.
Technical details
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CWE
- CWE-284
- Affected versions
- Papercut MF/NG; Papercut Papercut Mf (Start Including: 22.0.0, End Excluding: 22.0.9); Papercut Papercut Ng (Start Including: 22.0.0, End Excluding: 22.0.9)
- Published
- 20 April 2023
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
Signal timeline
- Added to CISA KEV
- Latest EPSS score: 100.0%
- Signal calculated at 88
External references
- Government advisory from www.cisa.gov
- Third-party advisory from packetstormsecurity.com
- Exploit information from packetstormsecurity.com
- Exploit information from packetstormsecurity.com
- Exploit information from packetstormsecurity.com
- Third-party advisory from news.sophos.com
- Vendor advisory from www.papercut.com
- Third-party advisory from www.zerodayinitiative.com