Detection rules › Splunk
JetBrains TeamCity RCE Attempt
The following analytic detects attempts to exploit the CVE-2023-42793 vulnerability in JetBrains TeamCity On-Premises. It identifies suspicious POST requests to /app/rest/users/id:1/tokens/RPC2, leveraging the Web datamodel to monitor specific URL patterns and HTTP methods. This activity is significant as it may indicate an unauthenticated attacker attempting to gain administrative access via Remote Code Execution (RCE). If confirmed malicious, this could allow the attacker to execute arbitrary code, potentially compromising the entire TeamCity environment and leading to further unauthorized access and data breaches.
Known false positives
- Requests to this specific endpoint via this method should not be common. Investigate further to determine if the request is legitimate, and apply appropriate filters to reduce false positives.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access |
Rule body
name: JetBrains TeamCity RCE Attempt
id: 89a58e5f-1365-4793-b45c-770abbb32b6c
version: 11
creation_date: '2023-10-01'
modification_date: '2026-05-13'
author: Michael Haag, Splunk
status: production
type: TTP
description: |-
The following analytic detects attempts to exploit the CVE-2023-42793 vulnerability in JetBrains TeamCity On-Premises.
It identifies suspicious POST requests to /app/rest/users/id:1/tokens/RPC2, leveraging the Web datamodel to monitor specific URL patterns and HTTP methods.
This activity is significant as it may indicate an unauthenticated attacker attempting to gain administrative access via Remote Code Execution (RCE).
If confirmed malicious, this could allow the attacker to execute arbitrary code, potentially compromising the entire TeamCity environment and leading to further unauthorized access and data breaches.
data_source:
- Suricata
search: |-
| tstats `security_content_summariesonly`
count min(_time) as firstTime
max(_time) as lastTime
FROM datamodel=Web WHERE
Web.url="*/app/rest/users/id:1/tokens/RPC2*"
Web.status=200
Web.http_method="POST"
BY Web.http_user_agent Web.status Web.http_method
Web.url Web.url_length Web.src Web.dest
| `drop_dm_object_name("Web")`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `jetbrains_teamcity_rce_attempt_filter`
how_to_implement: |-
The following analytic requires the Web datamodel. Ensure data source is mapped correctly or modify and tune for your data source.
known_false_positives: |-
Requests to this specific endpoint via this method should not be common. Investigate further to determine if the request is legitimate, and apply appropriate filters to reduce false positives.
references:
- https://blog.jetbrains.com/teamcity/2023/09/critical-security-issue-affecting-teamcity-on-premises-update-to-2023-05-4-now/
- https://www.sonarsource.com/blog/teamcity-vulnerability/
- https://github.com/rapid7/metasploit-framework/pull/18408
- https://attackerkb.com/topics/1XEEEkGHzt/cve-2023-42793/rapid7-analysis
finding:
title: Potential JetBrains TeamCity RCE Attempt detected against URL $url$ on $dest$.
entity:
field: dest
type: system
score: 50
threat_objects:
- field: src
type: ip_address
analytic_story:
- JetBrains TeamCity Unauthenticated RCE
- CISA AA23-347A
- JetBrains TeamCity Vulnerabilities
asset_type: Web Server
cve:
- CVE-2023-42793
mitre_attack_id:
- T1190
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
category: web
security_domain: network
Stages and Predicates
Stage 1: tstats
| tstats `security_content_summariesonly`
count min(_time) as firstTime
max(_time) as lastTime
FROM datamodel=Web WHERE
Web.url="*/app/rest/users/id:1/tokens/RPC2*"
Web.status=200
Web.http_method="POST"
BY Web.http_user_agent Web.status Web.http_method
Web.url Web.url_length Web.src Web.dest
Stage 2: search
| `drop_dm_object_name("Web")`
Stage 3: search
| `security_content_ctime(firstTime)`
Stage 4: search
| `security_content_ctime(lastTime)`
Stage 5: search
| `jetbrains_teamcity_rce_attempt_filter`
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
Web.http_method | eq |
| field:"cs-method" kind:eq |
Web.status | eq |
| field:"Web.status" kind:eq value:"200" |
Web.url | eq |
| field:"c-uri" kind:eq |