Threat Intelligence / CVE / CVE-2023-27351

CVE-2023-27351 — Papercut Mf

CVSS v3.1 7.5 (HIGH) · EPSS 44.7% (higher than 97.5% of all scored CVEs) · Priority 7.7/10 · Published 2023-04-20

As of 2024-11-21, CVE-2023-27351 is a HIGH-severity vulnerability in Papercut Mf, CVSS v3.1 7.5, EPSS 44.7% (97.5th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2023-27351, most recently “Storm-1175 Medusa Ransomware Zero-Day Exploitation Campaign (CVE-2026-23760, CVE-2025-10035)”.

Last updated: 2024-11-21

What is CVE-2023-27351?

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.

The record classifies CVE-2023-27351 under weakness class CWE-287. 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. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 1242 days ago.

Severity and exploitation probability

CVSS v3.1 base score: 7.5 — HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS (FIRST): 44.7% probability of exploitation in the next 30 days, higher than 97.5% of all scored CVEs
CISA KEV: Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority: 7.7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published: 2023-04-20, last modified 2024-11-21

Is CVE-2023-27351 being exploited?

It currently carries a trending score of 29 in the Threadlinqs vulnerability feed.

Affected products and versions

Papercut: Mf, Ng

How to fix CVE-2023-27351

Vendor advisory: https://www.papercut.com/kb/Main/PO-1216-and-PO-1219. 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-2023-27351

1 tracked threat in the Threadlinqs corpus references CVE-2023-27351, either in the campaign’s CVE list or as an indicator on the campaign record.

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.

Full detection coverage & IOCs for threats exploiting CVE-2023-27351 are available via the Threadlinqs MCP server (Purple tier). View plans →

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