Point hosts at TeamCity and flag CVE-2024-27199 (auth bypass) by version, then confirm by opening the REST path unauthenticated. Non-destructive. CISA KEV.
Opens the REST server path without credentials. Advisory
Detect
Fingerprints TeamCity and flags CVE-2024-27199 by version.
Report
Counts checked, product, affected, and confirmed.
Targets
Hosts, IPs, or URLs, one per line. Empty input uses localhost.
Overview
This workflow finds JetBrains TeamCity and sorts each host by whether its version falls in the CVE-2024-27199 range. A TeamCity server holds build secrets, agent tokens, and the path into production. CVE-2024-27199 is the path-traversal auth bypass on the REST surface. CISA listed it on KEV after in-the-wild use. A below-fix build is patch-lag you can prove from the version endpoint, not a guess from a banner. Give it hostnames, IP addresses, or URLs you are authorised to test. The workflow fingerprints the product from the public page (title match on TeamCity), reads the version from /app/rest/server with a fallback to the root body, and compares that number to the range table in the graph. Every host comes back affected or not, so a fleet advisory becomes an evidenced list for exposure management. CVE-2024-27199 is on CISA KEV (known exploited). Version flag is first. Hosts in range get a second node that opens the REST server path without credentials. It does not create accounts.
Run it on a schedule when the estate changes. New hosts and delayed patch windows are the reason the same check is worth more the second week than the first.
Pipeline
Read the target list. Hosts, URLs, or ranges, one per line, become the scope.
Fingerprint each host as JetBrains TeamCity from the public page title, then GET /app/rest/server and parse the version. A host counts as affected only when the fingerprint matches and the version is inside the encoded range.
Confirm only those flagged hosts by opening the REST server path without credentials.
Collect the per-host rows: product match, version, affected flag, confirmed flag, and any fetch error.
Emit the summary counts: hosts checked, product hits, affected, confirmed, and errors.
Inputs
Target list. Hostnames, IP addresses, CIDR ranges, or URLs, one per line. JSONL with a url field also works. Point it at scope you are authorised to test. Fingerprint is read-only GET. Confirm opens the REST server path without credentials, and only after the version flag.
Outputs
results.jsonl. One row per host: URL, whether JetBrains TeamCity was detected, the version read, the affected flag, and whether the REST-path confirm succeeded.
summary.json. Counts across the list: targets, product hits, affected, and errors.
Integrations
HTTP. Unauthenticated GET to the product root and /app/rest/server. Confirm opens the REST server path without credentials, only on flagged hosts.
Sample output
The records below are illustrative and do not come from a real run. They show one JetBrains TeamCity host inside the CVE-2024-27199 range, one patched host, and one host that is not the product.
every build before 2023.11.4. 2023.11.4 and later is the floor the graph treats as not affected. The compare uses the version the product itself served.
Does a flagged host mean CVE-2024-27199 was exploited?
No. A flagged row is patch-lag against the range table. Confirm only opens the REST server path without credentials. Treat a confirmed row as evidence the path still answers, not as proof someone already used it.
Is this check safe on production?
Yes. Fingerprint is read-only GET. Confirm opens the REST server path without credentials, only on hosts already in range. It does not log in, create accounts, or write files.
Does the check need credentials?
No. It fingerprints the public page and reads /app/rest/server the way an external scanner would.
What is CVE-2024-27199?
Authentication bypass in TeamCity via path traversal on the REST API. CISA listed it on KEV after confirmed exploitation. This workflow flags by version, then confirms by opening the REST server path without credentials.