Cyber Resilience

CVE-2023-39469

RCE in Papercut Mf ≤ 22.1.1

High EPSSRCE
Published
03 May 2024
Modified
30 January 2025
Patch / advisory
CVSS Score v3.1 7.2
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.58 99.0th percentile
Risk Priority 76 floored blend · peak EPSS

Summary

CVE-2023-39469 is a high-severity Code Injection (CWE-94) vulnerability in Papercut Papercut Mf. Its CVSS base score is 7.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 1.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

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-2023-39469 is a remote code execution vulnerability in PaperCut NG stemming from improper validation of a user-supplied string within the External User Lookup functionality. The flaw permits the string to be used directly for Java code execution, classified under CWE-94, and carries a CVSS 3.1 score of 7.2 reflecting network-accessible attack with high-privilege requirements but full system impact.

An authenticated remote attacker can supply a crafted string to the External User Lookup feature and achieve arbitrary code execution in the context of the SYSTEM account on affected PaperCut NG installations.

Public advisories from PaperCut and Zero Day Initiative detail the issue as ZDI-CAN-21013 and direct administrators to the July 2023 security bulletin for patch and mitigation guidance. The associated EPSS score rose materially from lower values to a peak of 0.6029 on 2025-12-11 before receding to the current 0.1658, indicating a period of heightened exploitation interest after disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

PaperCut NG External User Lookup Code Injection Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of PaperCut NG. Authentication is required to exploit this vulnerability. The specific flaw exists within the External…

more

User Lookup functionality. The issue results from the lack of proper validation of a user-supplied string before using it to execute Java code. An attacker can leverage this vulnerability to execute code in the context of SYSTEM. Was ZDI-CAN-21013.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1059.002 AppleScript Execution
Adversaries may abuse AppleScript for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1059.005 Visual Basic Execution
Adversaries may abuse Visual Basic (VB) for execution.
T1059.006 Python Execution
Adversaries may abuse Python commands and scripts for execution.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-8405Same product: Papercut Papercut Mf
CVE-2026-6180Same product: Papercut Papercut Mf
CVE-2023-3486Same product: Papercut Papercut Mf
CVE-2023-31046Same product: Papercut Papercut Mf
CVE-2023-2533Same product: Papercut Papercut Mf
CVE-2026-4794Same product: Papercut Papercut Mf
CVE-2024-9672Same product: Papercut Papercut Mf
CVE-2023-27351Same product: Papercut Papercut Mf
CVE-2023-27350Same product: Papercut Papercut Mf
CVE-2026-6418Same product: Papercut Papercut Mf

Affected Assets

papercut
papercut mf
≤ 22.1.1
papercut
papercut ng
≤ 22.1.1

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)
  • V1.3.1

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation finds code paths that accept and execute externally influenced strings.

Input validation directly stops untrusted data from being used to construct executable code without neutralization.

Least privilege limits the damage an injected code fragment can perform once executed.

Requiring documented secure development standards and tools enforces use of safe code-generation APIs and escaping.

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-06 mostly match
prevents

PR.PS-06's SDLC practices directly target injection flaws via secure coding and testing (mostly), yet as a single broad outcome it leaves many code-generation specifics unaddressed (partial).

PR.DS-10 none match
prevents

PR.DS-10 protects runtime data confidentiality/integrity but has no bearing on neutralizing externally influenced input during code generation, so neither direction shows any preventive effect.

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.

prevents

Banning unapproved code samples and unauthenticated web services, combined with secure-coding standards and SAST, prevents the dynamic generation or inclusion of attacker-supplied code.

none

Controls that restrict unauthorized or malicious code from being introduced via external networks or removable media limit opportunities for an attacker to inject and execute arbitrary code.

References