Comprehensive Analysis of CVE-2024-47951: JetBrains TeamCity Stored XSS Vulnerability

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1. Vulnerability Overview

CVE-2024-47951 is a stored Cross-Site Scripting (XSS) vulnerability in JetBrains TeamCity CI/CD platform, affecting versions prior to 2024.07.3. This medium-severity vulnerability (CVSS 5.4) enables attackers to inject malicious scripts through server global settings, potentially hijacking user sessions or altering UI behavior[1][14][16].

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2. Technical Deep Dive

Root Cause Analysis

The vulnerability arises from insufficient input validation in server global settings configurations. When these settings are modified, user-input data is stored without proper sanitization or escaping. This allows attackers to inject arbitrary HTML/JavaScript, which executes in the context of authenticated users’ browsers when they interact with the affected settings[14][16].

Exploitation Workflow

1. Attack Prerequisites:

1. Access to a TeamCity instance with permissions to modify server global settings (e.g., admin or granted roles)[14].
2. Ability to craft malicious scripts targeting browser contexts.
3. Injection Vector:
4. Modify a server global setting, such as backup configurations or build-related parameters, embedding XSS payloads like .
5. Example payload: alert('XSS');
6. Execution Triggers:
7. Victims interact with the affected settings page, causing the injected script to execute in their browser.
8. Impact: Session hijacking, unauthorized actions, malware distribution, or defacement of TeamCity interfaces[1][16].

Attack Limitations

1. User Interaction Required: Exploitation depends on the victim accessing a tainted page, reducing the vulnerability’s reach compared to stored XSS in more frequently visited areas[16].
2. Mitigation Barriers: Proper Content Security Policies (CSP) and input validation best practices can block script execution in modern browsers.

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3. Threat Intelligence and Active Exploitation

As of July 2025, no public reports of exploitation or organized campaigns targeting CVE-2024-47951 have surfaced. Key observations:

1. No Known PoC: Unlike other CVEs (e.g., CVE-2024-49112 in Windows LDAP), no proof-of-concept exploits or proof-of-exploits have been released for this vulnerability[5][12].
2. Low Priority for Threat Actors: Medium-severity XSS vulnerabilities are often deprioritized compared to critical RCE flaws (e.g., CVE-2024-49112, CVSS 9.8).
3. Monitoring Gaps: Limited references in public threat feeds (e.g., no mentions in CISA alerts or Rapid7’s Metasploit updates)[9][13].

Recommendation: While exploitation is unlikely, organizations should still treat this vulnerability with caution due to the potential for sophisticated attackers to chain it with other flaws (e.g., authentication bypass)[11].

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4. Vendor Response and Patching Guidance

JetBrains’ Remediation Efforts

1. Patch Distribution: The vulnerability was addressed in TeamCity 2024.07.3, released on October 1, 2024[3][7].
2. Upgrade Path:

1. Direct Update: Use TeamCity’s automatic update feature or download the patched version from JetBrains’ website.
2. Docker Images: Pull updated TeamCity Docker containers (Linux agent and server images).
3. Version Compatibility: The 2024.07.x line shares the same data format, enabling seamless upgrades/downgrades within this branch[3].

Critical Advisory for Unpatched Users


JetBrains did not release a standalone security patch plugin for this CVE—unlike their response to CVE-2024-23917, a critical authentication bypass[11]. Organizations must upgrade to 2024.07.3+ to resolve the issue.

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5. Supply Chain and CI/CD Pipeline Implications


Key Risks

1. Build Workflows Compromise: While stored XSS in global settings doesn’t directly affect build processes, a compromised environment could be manipulated to inject malicious scripts into build agents (e.g., via tampered environment variables).
2. Access to Sensitive Data: Attackers could exploit session hijacking to access credentials, build artifacts, or dependencies.

Detection and Prevention

| Strategy | Implementation | Example Tools/Methods |
|———————————-|————————————|—————————————-|
| Input Validation | Enforce Sanitization via Plugins | OWASP ESAPI, Custom WAF Rules |
| Audit Logs | Monitor Server Settings Modifications | TeamCity Audit Logs, SIEM Alerts |
| CI/CD Pipeline Hardening | Restrict Build Agent Permissions | Least-Privilege Runner Configurations |

Best Practice: Isolate sensitive CI/CD environments from untrusted users and enforce strict role-based access control (RBAC) for server settings[3][8].

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6. Detection and Monitoring Strategies

SIEM Detection Rules

Query TeamCity logs for:

event_type="config_change" AND parameter_name="server.global.settings" AND (XSSPayloadMatch OR inject_CT)

Adapted from generic XSS detection patterns. Replace with exact field names from TeamCity logs.

Network Monitoring Signatures

1. HTTP Request Analysis: Detect suspicious scripts injected into application/x-www-form-urlencoded payloads targeting TeamCity’s backend APIs[17].
2. Juniper Signature: Detects attempts to exploit Backup History XSS (signature ID HTTP:XSS:JTBRAIN-TM-CTY-BKP-HIS)[17].

Behavioral Indicators

1. Unusual SSO Activity: Monitor for unexpected login events or session tokens being triggered from atypical browsers/devices.
2. Artifact Modifications: Audit suspicious changes to build scripts, environment variables, or pipeline definitions.

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7. Advanced Mitigation and Hardening

Configuration-Based Mitigations

| Measure | Implementation Steps |
|———————————-|————————————————|
| CSP Headers | Enforce Content-Security-Policy: script-src 'self' to block unauthorized script execution. |
| User Permissions | Limit access to server global settings to trusted administrators only. |
| Regular Audits | Conduct routine security audits of TeamCity configurations and logs. |

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Conclusion

CVE-2024-47951 highlights the importance of maintaining secure configurations within CI/CD tools like JetBrains TeamCity. Organizations should prioritize patching to mitigate potential risks associated with stored XSS vulnerabilities, ensuring robust security practices are in place to protect sensitive data and workflows.

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References

1. Recorded Future
2. Red Hat Customer Portal
3. JetBrains Blog
4. Rapid7
5. CISA
6. Infosecurity Magazine
7. Juniper Networks
8. GitHub Advisory