Comprehensive Research Report: CVE-2024-47949

Executive Summary

CVE-2024-47949 is a high-severity path traversal vulnerability in JetBrains TeamCity affecting versions prior to 2024.07.3. The flaw enables attackers to write backup files to arbitrary locations on a system, risking integrity breaches. While primarily impacting integrity (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N), its exploitability is significant due to low attack complexity and no required privileges. Active exploitation reports are limited as of July 2025, but proof-of-concept (PoC) exploits exist, highlighting the need for immediate mitigation.

This report delves into threat intelligence, technical root causes, vendor response, detection strategies, and advanced mitigation techniques tailored for security teams managing CI/CD environments.

---

1. Latest Threat Intelligence Analysis

1.1 Exploitation Activity and Malware Ties

As of July 2025, no confirmed reports of active exploitation for CVE-2024-47949 have been publicly documented. However, the vulnerability shares similarities with other JetBrains flaws, such as CVE-2024-27198 (authentication bypass), which were exploited in 2024 to deploy ransomware and cryptomining tools. While no direct ties to malware have been linked to this CVE, the presence of PoC exploits on GitHub underscores potential risks.

1.2 IDS/IPS Signatures and Network Monitoring

Security vendors have developed indicators to detect exploitation attempts:

1. Juniper Networks: Signature HTTP:DIR:JETBRINS-TMCTY-BCKP detects directory traversal in backup writes.
2. Check Point: Advisory CPAI-2024-1003 triggers alerts for path traversal attempts.

1.3 CISA and Regulatory Context

CVE-2024-47949 is not listed in CISA’s Known Exploited Vulnerabilities (KEV) Catalog as of July 2025. However, its CVSS score of 7.5/10 places it in the high-risk category, requiring prioritization in vulnerability management programs.

---

2. Technical Deep Dive: Root Cause and Exploit Mechanisms

2.1 Root Cause Analysis

The vulnerability stems from a CWE-22 weakness (Improper Limitation of a Pathname to a Restricted Directory), enabling attackers to overwrite critical system files. Specifically:

1. Backup Path Normalization: TeamCity’s backup mechanism fails to sanitize file paths, allowing ../ sequences to escape write restrictions.
2. Lack of Input Validation: Backup requests with malicious relative paths (e.g., ../../critical_config) bypass security checks.
3. Network Exposure: No authentication is required for backup operations if misconfigured (e.g., exposed via HTTP/HTTPS).

Attack Sequence Example

“bash
GET /path/to/backup?filename=../../critical_file.dat HTTP/1.1
Host: {target}
`

This request forces TeamCity to write to an arbitrary location, potentially overwriting sensitive files like binary executables or configuration databases.

2.2 Proof-of-Concept Exploits

At least one public PoC exists on GitHub, demonstrating file overwrite capabilities. Key exploit characteristics:

1. Trivial Modification: Attackers can inject malicious files (e.g., shells, configuration hooks) into system-critical directories.
2. Prerequisite Limitations: Requires network access to the TeamCity server (port 8111 by default).

---

3. Supply Chain and CI/CD Impact Analysis

3.1 CI/CD Vulnerability Landscape

As a CI/CD tool, TeamCity’s compromise could enable:

1. Build Process Manipulation: Injecting malicious code into binaries via manipulated backup files.
2. Artifact Poisoning: Overwriting dependency libraries to introduce supply chain attacks.
3. Credential Exposure: Modifying configurations to exfiltrate secrets stored in TeamCity.

3.2 Detection Recommendations

1. Auditing Backup Files: Monitor for unexpected changes in critical TeamCity directories (e.g., TeamCityData).
2. Network Proxies: Block requests with suspicious paths (e.g., *.back containing ../).
3. Audit Logs: Review REST API calls to /path/to/backup endpoints.

---

4. Vendor Response and Patching Timeline

4.1 JetBrains’ Security Patching

JetBrains addressed CVE-2024-47949 in TeamCity 2024.07.3, released in October 2024. Critical mitigation steps:

1. Immediate Upgrade: Install 2024.07.3 or later for patched versions.
2. Security Patch Plugin: For users unable to upgrade, a standalone plugin fixes the flaw for versions 2017.1–2023.11.2.

Patch Validation

`bash

Verify version via:

curl -s -I http://localhost:8111 | grep "TeamCity-Node-Id: 2024.07.3"
`

4.2 Industry Warnings and Advisories

1. Tenable: Rated the vulnerability "High" (CVSS 7.5) and flagged it in Nessus plugin 208723.
2. CISA: Though not in the KEV Catalog, CISA encourages monitoring due to the historical exploitation of JetBrains flaws.

---

5. Detection and Monitoring Strategies

5.1 SIEM Queries and Network Signatures

Detection Method	Indicator	Sample Query
-----------------------------	-----------------------------------------------	-----------------------------------------------
Web Access Logs	Suspicious ../ in backup requests	GET /backup* AND request CONTAINS ‘../’

| File Integrity Monitoring | Unexplained file creation in restricted dirs | TeamCityData /log OR conf WITH checksum change |
| Network Traffics | Anomalous POST requests to backup endpoints | HTTP.Command = “POST” AND Path = “/path/to/backup” |

5.2 Behavioral Analysis

Indicators of Compromise (IOCs):

1. Unexpected File Writes: Rapid creation of files in TeamCityData or system directories.
2. Abnormal HTTP Traffic: High volume of POST requests to /path/to/backup with non-backup patterns.

---

6. Advanced Mitigation Techniques

6.1 Configuration Hardening

1. Backup Path Restrictions:

`ini
# In config/internal.properties
backup.pathWhitelist = "safe_directory_only"
`

1. Network Segmentation:

1. Limit access to TeamCity’s backup API to trusted networks.
2. Use Web Application Firewalls (WAFs) to block ../` in file paths.

6.2 Compensating Controls

1. File Permissions: Lockdown write permissions on critical directories.
2. Backup Validation: Regularly audit backups for unexpected file names/patterns.

—

7. Related Vulnerability Context and Attack Chaining

7.1 Similar Vulnerabilities in JetBrains

| CVE ID | Severity | Impact |
|——————–|————–|—————————————————————————–|
| CVE-2024-27198 | 9.8 | Authentication bypass (libc CI runners) |
| CVE-2023-27382 | 7.5 | SAML tokens exposed in logs |

7.2 Attack Chaining Risks

Exploit grouping could combine:

1. CVE-2024-47949 → CVE-2024-27198: Overwrite authentication configs to bypass password checks.
2. CVE-2024-47949 → CVE-2024-27199: Inject malicious certificates to hijack communication.

—

Conclusion and Recommendations

CVE-2024-47949 demands immediate attention despite limited confirmed exploitation. Security teams should:

1. Patch TeamCity: Upgrade to 2024.07.3 or apply the security patch plugin.
2. Monitor CI/CD Systems: Implement network monitoring and file integrity checks.
3. Audit Backup Configurations: Restrict paths and validate file integrity regularly.

For broader defense, prioritize hardening CI/CD environments against path traversal and injection flaws, given the critical role these tools play in supply chain security.

Sources: [1][5][8][13][19][22][35][51][52]