Try in Splunk Security Cloud

Description

The CVE-2024-27198 vulnerability presents a critical security risk for JetBrains TeamCity on-premises servers, allowing attackers to bypass authentication mechanisms and gain unauthorized access. This vulnerability can be exploited in several ways, each leading to the attacker gaining full control over the TeamCity server, including all associated projects, builds, agents, and artifacts. One method of exploitation involves creating a new administrator user. An attacker, without needing to authenticate, can send a specially crafted POST request to the /app/rest/users REST API endpoint. This request includes the desired username, password, email, and roles for the new user, effectively granting them administrative privileges upon successful execution. Alternatively, an attacker can generate a new administrator access token by targeting the /app/rest/users/id:1/tokens endpoint with a POST request. This method also does not require prior authentication and results in the creation of a token that grants administrative access. Both exploitation methods underscore the severity of the CVE-2024-27198 vulnerability and highlight the importance of securing TeamCity servers against such authentication bypass threats. The manipulation of URI paths /app/rest/users and /app/rest/users/id:1/tokens through malicious requests enables attackers to gain unauthorized access and control, emphasizing the need for immediate remediation measures.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Web
  • Last Updated: 2024-03-04
  • Author: Michael Haag, Splunk
  • ID: fbcc04c7-8a79-453c-b3a9-c232c423bdd4

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1190 Exploit Public-Facing Application Initial Access
Kill Chain Phase
  • Delivery
NIST
  • DE.CM
CIS20
  • CIS 13
CVE
ID Summary CVSS
CVE-2024-27198 In JetBrains TeamCity before 2023.11.4 authentication bypass allowing to perform admin actions was possible None 


1
2
3
4
5
6



| tstats count min(_time) as firstTime max(_time) as lastTime from datamodel=Web where ((Web.url="*?jsp=*" AND Web.url="*;.jsp*") Web.status=200 Web.http_method=POST) OR (Web.url IN ("*jsp=/app/rest/users;.jsp","*?jsp=/app/rest/users;.jsp","*?jsp=.*/app/rest/users/id:*/tokens;*") Web.status=200 Web.http_method=POST ) by Web.src, Web.dest, Web.http_user_agent, Web.url, Web.status, Web.http_method, sourcetype, source 
| `drop_dm_object_name("Web")` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)`
| `jetbrains_teamcity_authentication_bypass_cve_2024_27198_filter`

Macros

The SPL above uses the following Macros:

:information_source: jetbrains_teamcity_authentication_bypass_cve-2024-27198_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • Web.src
  • Web.dest
  • Web.http_user_agent
  • Web.url
  • Web.status
  • Web.http_method
  • sourcetype
  • source

How To Implement

The detection relies on the Web datamodel and a CIM compliant log source, that may include Nginx, TeamCity logs, or other web server logs.

Known False Positives

False positives are not expected, as this detection is based on the presence of specific URI paths and HTTP methods that are indicative of the CVE-2024-27198 vulnerability exploitation. Monitor, filter and tune as needed based on organization log sources.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
81.0 90 90 Possible JetBrains TeamCity Authentication Bypass CVE-2024-27198 Attempt against $dest$ from $src$.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 1