CVE-2020-7908 in TeamCity
Summary
by MITRE
In JetBrains TeamCity before 2019.1.5, reverse tabnabbing was possible on several pages.
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Analysis
by VulDB Data Team • 01/31/2020
The vulnerability identified as CVE-2020-7908 affects JetBrains TeamCity versions prior to 2019.1.5 and represents a reverse tabnabbing security flaw that can be exploited through multiple web pages within the application. This type of vulnerability occurs when a web page opens links in new tabs or windows without properly setting the rel="noopener" attribute, creating a potential attack vector where malicious actors can manipulate the original page's window object through the newly opened tab.
Reverse tabnabbing attacks leverage the window.opener property that browsers automatically set when a new tab is opened via target="_blank" without thenoopener attribute. When an attacker controls the content of the newly opened tab, they can access the window.opener property to gain control over the original page, potentially leading to cross-site scripting attacks, session hijacking, or information disclosure. This vulnerability specifically impacts TeamCity's user interface where links are rendered without proper security attributes, making it possible for attackers to exploit this weakness through crafted malicious content.
The operational impact of this vulnerability extends beyond simple information disclosure as it creates a persistent attack surface within the TeamCity application. Organizations using affected versions may experience compromised build server integrity, unauthorized access to sensitive project configurations, and potential escalation to full system compromise if attackers can leverage the opened tab manipulation for more sophisticated attacks. The vulnerability affects the application's web interface components that handle external links, user navigation, and third-party integrations, making it particularly concerning for development environments where TeamCity serves as a central automation hub.
Teams utilizing JetBrains TeamCity should immediately upgrade to version 2019.1.5 or later to remediate this vulnerability, as the fix involves implementing proper security attributes on all external links within the application. The mitigation strategy aligns with industry best practices for preventing reverse tabnabbing attacks and should be complemented by regular security assessments of web applications. This vulnerability demonstrates the importance of maintaining up-to-date security controls in development tools and highlights the need for comprehensive security testing of web interfaces, particularly those handling user-generated content or external references. The issue can be mapped to CWE-1021, which specifically addresses improper certificate validation and related security flaws in web applications, and aligns with ATT&CK technique T1190, which covers exploiting vulnerabilities in web applications through malicious link manipulation. Organizations should also implement proper input validation and output encoding controls to prevent similar issues in other web-based systems within their infrastructure.