ClosedPatched

PaperCut MF/NG auth bypass to SYSTEM RCE, used by Cl0p and LockBit (CVE-2023-27350)

PaperCut MF and PaperCut NG

An improper access control bug in PaperCut NG/MF print management let unauthenticated attackers run code as SYSTEM. Fixes had shipped in March 2023, but unpatched servers were exploited from April. Microsoft linked it to Cl0p (Lace Tempest) and LockBit, and the Bl00dy gang hit schools with it.

Why this severity: CVSS 9.8 (NVD), actively exploited (CISA KEV), known ransomware use

Started: Apr 21, 2023
Closed: May 11, 2023
CVE: CVE-2023-27350

Follow this incident

Updated May 11, 2023

Affected

See vendor advisory

Fixed in

20.1.7
21.2.11
22.0.9

Timeline2

May 11, 2023
CISA and FBI advisory AA23-131A: Bl00dy Ransomware Gang targeting education via PaperCut
Source
Apr 21, 2023
PaperCut warns that unpatched servers are being exploited in the wild; CISA adds CVE-2023-27350 to KEV
Source

Advisories4

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