CVE-2023-39469: PaperCut NG External User Lookup Code Injection Remote Code Execution Vulnerability

Severity: high (CVSS 7.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 61.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-03 · updated 2026-06-17
Weakness: CWE-94

Description

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 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.

Affected products

PaperCut MF: before 22.1.1 — fixed in 22.1.1
PaperCut NG: before 22.1.1 — fixed in 22.1.1

How to fix

Upgrade to a fixed version: PaperCut MF 22.1.1; PaperCut NG 22.1.1. Check the vendor advisory for mitigations.

References

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