1. Cleus
  2. Zero-days
  3. CVE-2023-27350
Exploited in the wildUsed by ransomwareServers & business softwareWork IT

CVE-2023-27350 PaperCut MF/NG: login or permission bypass

In plain words: A door that should be locked is not: part of the system can be reached without a valid login or permission. The attacker gets in as a user or administrator without knowing a password.

Confirmed exploited by CISA on · US federal patch deadline May 12, 2023

What to do

  1. Install PaperCut's security update for MF/NG. If no update exists, follow the vendor's workaround or stop using the product until one ships.
  2. Keep a list of every internet-facing server you run so nothing is forgotten.
  3. Patch anything in this catalog first, ahead of normal patch cycles.
  4. Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.

Read PaperCut's advisory ↗

Who is affected

Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.

The details

Official name
PaperCut MF/NG Improper Access Control Vulnerability
Product
PaperCut MF/NG
CISA description
PaperCut MF/NG contains an improper access control vulnerability within the SetupCompleted class that allows authentication bypass and code execution in the context of system.
Type of flaw
Login or permission bypass (CWE-284)
Confirmed exploited
Apr 21, 2023 — known to be used in ransomware attacks
US federal patch deadline
May 12, 2023

Ask Cleus about it

Ask about a vulnerability, an update, a weird message, or the news. Plain-word answers, free, no account.

Answering about CVE-2023-27350 ·

Questions about CVE-2023-27350

Is CVE-2023-27350 being exploited?

Yes. CISA added CVE-2023-27350 to its Known Exploited Vulnerabilities catalog on Apr 21, 2023, which means there is reliable evidence of real-world attacks, including by ransomware groups.

How do I fix CVE-2023-27350?

Install PaperCut's security update for MF/NG. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.

Am I affected by CVE-2023-27350?

Only if you use PaperCut MF/NG. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

Other exploited PaperCut vulnerabilities

Newest in the catalog

Search every known exploited vulnerability →