CVE-2023-27350 — Papercut Mf
CISA KEVRansomwareAs of 2025-10-27, CVE-2023-27350 is a CRITICAL-severity vulnerability in Papercut Mf, CVSS v3.1 9.8, EPSS 94.2% (99.9th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-04-21), with a US federal remediation deadline of 2023-05-12, and CISA links it to known ransomware campaigns. Threadlinqs Intelligence links 3 tracked threat campaigns to CVE-2023-27350, most recently “LockBit 5.0 Ransomware Extortion Claim Against US Bank (U.S. Bancorp)”.
Last updated: 2025-10-27
What is CVE-2023-27350?
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.
The record classifies CVE-2023-27350 under weakness classes CWE-284, NVD-CWE-Other. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 1241 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS (FIRST)
- 94.2% probability of exploitation in the next 30 days, higher than 99.9% of all scored CVEs
- CISA KEV
- Listed since 2023-04-21, federal remediation deadline 2023-05-12 — used in known ransomware campaigns
- Threadlinqs priority
- 10/10 — CISA lists it as used in ransomware, which Threadlinqs scores at the maximum
- Published
- 2023-04-20, last modified 2025-10-27
Is CVE-2023-27350 being exploited?
CISA added CVE-2023-27350 to the Known Exploited Vulnerabilities catalog on 2023-04-21, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2023-05-12 under BOD 22-01. CISA flags the vulnerability as one used in known ransomware campaigns. It currently carries a trending score of 40 in the Threadlinqs vulnerability feed.
Affected products and versions
- Papercut: Mf, Ng
How to fix CVE-2023-27350
Vendor advisory: https://www.papercut.com/kb/Main/PO-1216-and-PO-1219. Because CVE-2023-27350 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2023-05-12. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2023-27350
3 tracked threats in the Threadlinqs corpus reference CVE-2023-27350, either in the campaign’s CVE list or as an indicator on the campaign record.
- LockBit 5.0 Ransomware Extortion Claim Against US Bank (U.S. Bancorp) — HIGH · 2026-08-21
- Proofpoint AI Era Ransomware Report: 37% of Paying Victims Face Repeat Extortion Demands — MEDIUM · 2026-07-22
- Storm-1175 Medusa Ransomware Zero-Day Exploitation Campaign (CVE-2026-23760, CVE-2025-10035) — CRITICAL · 2026-04-06
Sources
Seeded from nvd and not yet processed by the Threadlinqs enrichment pipeline, so blank CVSS, EPSS or KEV fields above mean NOT MEASURED rather than measured-absent.
- packetstormsecurity.com
- packetstormsecurity.com (PaperCut NG MG 22.0.4 Authentication Byp)
- packetstormsecurity.com (PaperCut NG MG 22.0.4 Remote Code Execut)
- packetstormsecurity.com (PaperCut PaperCutNG Authentication Bypas)
- news.sophos.com
- papercut.com
- zerodayinitiative.com
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