Threats / PaperCut / CVE-2023-27350
CVE-2023-27350
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
PaperCut MF/NG vulnerability
PaperCut MF/NG contains an improper access control vulnerability in the SetupCompleted class enabling authentication bypass and system-level code execution.
Verdict
Today item, not a backlog item.
An unauthenticated attacker can bypass authentication controls and execute arbitrary code with system privileges on affected PaperCut MF/NG installations. This vulnerability is actively exploited in the wild and associated with ransomware campaigns.
CISA KEV Yes · 2023-04-213Ransomware use Flagged3EPSS 0.99999 (verify live)4Exploit Weaponized · public PoC5
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
764 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-04-21), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.99999 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: PaperCut, MF/NG. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-284 Improper Access Control — weakness family: Authorization / access control.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I identify the SetupCompleted endpoint lacks proper access control validation.
Business
Attackers gain unauthenticated access to a critical administrative interface.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I bypass authentication checks and reach code execution functionality.
Business
System integrity is compromised as arbitrary code runs with elevated privileges.
3
Lateral reach — past segmentation narrative 3
Attacker
I execute malicious payloads in the system context to establish persistence.
Business
Infrastructure is fully compromised, enabling data theft and ransomware deployment.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05
Coverage & confidence
— what we know, and what we don’tEstablished (cited)
Coverage gaps — stated, not hidden
Disclosure & credit2
Catalogued by zdiCNA
Credited with finding itAnonymousunspecified