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  3. CVE-2023-42793
Exploited in the wildUsed by ransomwareServers & business softwareWork IT

CVE-2023-42793 JetBrains TeamCity: 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 Oct 25, 2023

What to do

  1. Install JetBrains's security update for TeamCity. 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 JetBrains'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
JetBrains TeamCity Authentication Bypass Vulnerability
Product
JetBrains TeamCity
CISA description
JetBrains TeamCity contains an authentication bypass vulnerability that allows for remote code execution on TeamCity Server.
Type of flaw
Login or permission bypass (CWE-288)
Confirmed exploited
Oct 4, 2023 — known to be used in ransomware attacks
US federal patch deadline
Oct 25, 2023

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Answering about CVE-2023-42793 ·

Questions about CVE-2023-42793

Is CVE-2023-42793 being exploited?

Yes. CISA added CVE-2023-42793 to its Known Exploited Vulnerabilities catalog on Oct 4, 2023, which means there is reliable evidence of real-world attacks, including by ransomware groups.

How do I fix CVE-2023-42793?

Install JetBrains's security update for TeamCity. 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-2023-42793?

Only if you use JetBrains TeamCity. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

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