CVE-2023-27351 kev+ ransomware in the critical feed json
This vulnerability allows remote attackers to bypass authentication on affected installations of PaperCut NG 22.0.5 (Build 63914).
published 2023-04-20 3 y ago modified 2026-10-01 38 d ago also EUVD-2023-31127
- cvss
- 8.2
- version 3.0, CNA
- cisa kev
- Exploited
- added 2026-04-20, used in ransomware
- epss
- 78.1%
- EPSS 78.1% chance of exploitation in 30 days, percentile 99.5%
- public exploits
- 0
- none known, plus a Nuclei check
Summary
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 SecurityRequestFilter class. The issue results from improper implementation of the authentication algorithm. An attacker can leverage this vulnerability to bypass authentication on the system. Was ZDI-CAN-19226.
Patch / fix
cisa required action Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- papercut papercut_mf 20.1.7, 21.2.11, 22.0.9
- papercut papercut_ng 20.1.7, 21.2.11, 22.0.9
Timeline
- Published
- Added to CISA KEV
- CISA SSVC: exploitation active
- CISA patch deadline
Known exploited
- Added
- 6 mo ago
- Patch by
- 2026-05-04 (6 mo ago)
- Ransomware
- Known to be used in ransomware campaigns
- Required action
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Vendor, product
- PaperCut, NG/MF
- CISA name
- PaperCut NG/MF Improper Authentication Vulnerability
CISA SSVC
- Exploitation
- Active, exploited in the wild
- Automatable
- yes
- Technical impact
- total
- Assessed
- 6 mo ago
Exploit prediction
78.05% chance of exploitation in the next 30 days, higher than 99.5% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- Nuclei template PaperCut NG - Authentication Bypass nuclei detection template
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.0 | 8.2 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N |
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
Affected products
- PaperCut NG
Classification
- Weakness
-
- CWE-287 Improper Authentication
References
-
papercut.com
/kb/Main/PO-1216-and-PO-1219
vendor-advisory
-
zerodayinitiative.com
/advisories/ZDI-23-232/
third-party-advisory, vdb-entry
-
cisa.gov
/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-27351
government-resource, us-government-resource
Sources
- CVE List CVE-2023-27351
- NVD CVE-2023-27351
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