JetBrains TeamCity Authentication Bypass Vulnerability
JetBrains · TeamCity
The flaw is an authentication bypass in the TeamCity component of JetBrains' TeamCity product, affecting versions before 2023.05.4. An unauthenticated remote attacker over the network can bypass authentication and achieve remote code execution on the TeamCity Server, with no user interaction or prior credentials required.
In JetBrains TeamCity before 2023.05.4 authentication bypass leading to RCE on TeamCity Server was possible
- Exploited
- Yes, in CISA KEV
- Reports
- 0
- Tactics
- 2/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited 12 days after disclosure. Public exploit code (Metasploit) was available the same day.
- First seen exploitedVulnCheck KEV evidence+12 days
- Added to CISA KEVknown ransomware use; EU database agrees+15 days
CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
2 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order 2Initial AccessTA0001
This vulnerability is exploited through an authentication bypass in JetBrains TeamCity, allowing remote attackers with HTTP(S) access to perform unauthorized remote code execution. This vulnerability enables attackers to gain administrative control of the TeamCity server and execute cmd.exe for various malicious activities, including downloading and executing harmful files.
ExecutionTA0002
Detection
0 rules for this CVE · 195 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2023-42793 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
Exploit Public-Facing ApplicationT1190149 general rules
- Arcadyan Router Exploitationscriticaltest
- Citrix ADS Exploitation CVE-2020-8193 CVE-2020-8195criticaltest
- Citrix Netscaler Attack CVE-2019-19781criticaltest
- Confluence Exploitation CVE-2019-3398criticaltest
- CVE-2010-5278 Exploitation Attemptcriticaltest
- CVE-2020-0688 Exchange Exploitation via Web Logcriticaltest
- CVE-2020-10148 SolarWinds Orion API Auth Bypasscriticaltest
- CVE-2020-5902 F5 BIG-IP Exploitation Attemptcriticaltest
Windows Command ShellT1059.00346 general rules
- Elise Backdoor Activitycriticaltest
- Rorschach Ransomware Execution Activitycriticaltest
- ZxShell Malwarecriticaltest
- HackTool - CrackMapExec Execution Patternshighstable
- AWS EC2 Startup Shell Script Changehightest
- Conhost.exe CommandLine Path Traversalhightest
- Exploited CVE-2020-10189 Zoho ManageEnginehightest
- Exploiting SetupComplete.cmd CVE-2019-1378hightest
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Not named in any threat report yetAlso mentioned in 50 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Actively_Exploited_Kev | Oct 30, 202629 Oct 2026
- Actively_Exploited_Kev | Oct 29, 202628 Oct 2026
- Actively_Exploited_Kev | Oct 28, 202627 Oct 2026
- Actively_Exploited_Kev | Oct 27, 202626 Oct 2026
- Actively_Exploited_Kev | Oct 24, 202623 Oct 2026
- Actively_Exploited_Kev | Oct 23, 202622 Oct 2026
- 44 more on OTX