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CVE-2023-27351

Improper Authentication: Is CVE-2023-27351 real, exploitable, or a false positive? Here's the community verdict.

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signals

public sources

Exploited in wild
Yes
CISA KEV
Public exploit
None known
Metasploit/EDB/PoC
Base severity
7.5 High
CVSS
Exploitation prob.
77%
FIRST EPSS
Weakness
CWE-287 · Improper Authentication
CWE

Confirmed exploited in the wild. Patch this first, regardless of the base score.

baseline read

auto · not a community verdict

Real — exploited in the wild

CISA confirms active exploitation. Treat scanner hits as true positives unless your specific version or config is unaffected.

Based on CISA KEV

Confirm or dispute →
Affected:Papercut

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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.

References

NVD MITRE CVE.org CISA KEV

Published

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In your experience, is this finding real and exploitable?

awaiting field verdicts
Real, but not a risk here
Not a real issue

Curated baseline: TruePositive's read from public sources is Real & exploitable — a starting point, not a community verdict.

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Field notes & remediation

Verdicts are the quick signal. Notes are the evidence and fixes behind them.

  • 0
    Field note · TruePositive EditorialCurated

    PaperCut NG/MF Improper Authentication Vulnerability — PaperCut NG/MF contains an improper authentication vulnerability that could allow remote attackers to bypass authentication on affected installations via the SecurityRequestFilter class. Listed in the CISA KEV catalog (added 2026-04-20) — confirmed exploited in the wild, not theoretical. It is linked to known ransomware campaigns. FIRST EPSS puts the chance of exploitation in the next 30 days at ~77%. Treat it as real and prioritize remediation over triage.

  • 0
    Remediation · TruePositive EditorialCurated

    Required action for PaperCut NG/MF: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. CISA set a federal remediation due date of 2026-05-04. After patching, verify the vulnerable path is no longer reachable before closing the finding.

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Related CVEs

Same weakness: CWE-287 · Improper Authentication.