Security Resilience

CVE-2023-39143

Path Traversal in Papercut Mf ≤ 22.1.3

Public PoCHigh EPSSPath Traversal
Published
04 August 2023
Modified
05 May 2025
Patch / advisory
View advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.80 99.6th percentile
Risk Priority 97 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-39143 is a critical-severity Path Traversal (CWE-22) vulnerability in Papercut Papercut Mf. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked in the top 0.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2023-39143 is a path traversal vulnerability affecting PaperCut NG and PaperCut MF versions prior to 22.1.3 running on Windows. The flaw, tracked under CWE-22, permits unauthorized upload, read, or deletion of arbitrary files on the server and can result in remote code execution when the commonly enabled external device integration feature is active. It carries a CVSS 3.1 base score of 9.8.

Unauthenticated attackers with network access can exploit the issue to achieve full compromise of the affected PaperCut installation, including arbitrary file operations that lead to code execution. No user interaction or credentials are required, and the attack surface is exposed by default in typical deployments.

Vendor guidance from PaperCut directs administrators to upgrade immediately to version 22.1.3 or later. Horizon3 research publications provide additional technical details on the flaw and recommended defensive steps.

The vulnerability maintains a high EPSS score with a recorded peak of 0.9209 and current value of 0.8818, indicating sustained exploitation interest following disclosure.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability Data

PaperCut NG and PaperCut MF before 22.1.3 on Windows allow path traversal, enabling attackers to upload, read, or delete arbitrary files. This leads to remote code execution when external device integration is enabled (a very common configuration).

CWE(s)
CWE-22

Related Threats

Threat-Actor AttributionAI

Cl0p (G0092)aka TA505
Cl0p ransomware exploited PaperCut NG/MF path-traversal RCE (incl. CVE-2023-39143) in July 2023 mass campaign per Mandiant, Sophos, and Unit 42 reporting.

MITRE ATT&CK Enterprise Techniques

T1001 Data Obfuscation Command And Control
Adversaries may obfuscate command and control traffic to make it more difficult to detect.
attack.mitre.org →
T1003.003 NTDS Credential Access
Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights.
attack.mitre.org →
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
attack.mitre.org →
T1003.006 DCSync Credential Access
Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citati…
attack.mitre.org →
T1016.001 Internet Connection Discovery Discovery
Adversaries may check for Internet connectivity on compromised systems.
attack.mitre.org →
T1018 Remote System Discovery Discovery
Adversaries may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for Lateral Movement from the current system.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-31046Same product: Papercut Papercut Mf
CVE-2025-11001Same product: Microsoft Windows
CVE-2024-8752Same product: Microsoft Windows
CVE-2025-1915Same product: Microsoft Windows
CVE-2024-7263Same product: Microsoft Windows
CVE-2026-25228Same product: Microsoft Windows
CVE-2026-25766Same product: Microsoft Windows
CVE-2024-49766Same product: Microsoft Windows
CVE-2023-2270Same product: Microsoft Windows
CVE-2023-5257Same product: Microsoft Windows

Affected Assets

papercut
papercut mf
≤ 22.1.3
papercut
papercut ng
≤ 22.1.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V5.3.2

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-10 Information Input Validation
addresses: CWE-22

Validates pathnames and filenames to prevent traversal outside intended directories.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-02 partial match
blocks

Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.

PR.AA-05 none match
blocks

PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

References