CVE-2015-8508 in Bugzilla
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in showdependencygraph.cgi in Bugzilla 2.x, 3.x, and 4.x before 4.2.16, 4.3.x and 4.4.x before 4.4.11, and 4.5.x and 5.0.x before 5.0.2, when a local dot configuration is used, allows remote attackers to inject arbitrary web script or HTML via a crafted bug summary.
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Analysis
by VulDB Data Team • 07/02/2022
The CVE-2015-8508 vulnerability represents a critical cross-site scripting flaw in Bugzilla's showdependencygraph.cgi component affecting multiple versions from 2.x through 5.0.x. This vulnerability specifically targets the dependency graph visualization feature that displays bug relationships within the Bugzilla issue tracking system. The flaw occurs when Bugzilla is configured to use a local dot configuration, which is a graph visualization tool that generates dependency graphs showing relationships between bugs. The vulnerability arises from insufficient input validation and output sanitization of bug summary fields, allowing malicious actors to inject arbitrary web scripts or HTML content directly into the dependency graph visualization. This type of vulnerability falls under CWE-79 which specifically addresses Cross-Site Scripting flaws in web applications. The attack vector leverages the fact that user-supplied bug summaries are directly rendered in the dependency graph without proper HTML escaping or sanitization, creating an environment where malicious payloads can be executed within the context of authenticated users' browsers.
The operational impact of this vulnerability extends beyond simple script execution as it enables attackers to perform various malicious activities through the dependency graph feature. An attacker can craft a bug summary containing malicious JavaScript code that gets executed when other users view the dependency graph, potentially leading to session hijacking, credential theft, or redirection to malicious sites. The vulnerability is particularly dangerous because Bugzilla is widely used by organizations for tracking security issues and development bugs, making it a prime target for attackers seeking to exploit the trust relationships inherent in issue tracking systems. When users with administrative privileges view the dependency graph, the attacker's malicious code could potentially execute with elevated privileges, though this depends on the specific implementation details and user permissions within the Bugzilla instance. The vulnerability demonstrates a classic weakness in web application security where user input is not properly validated or sanitized before being rendered in web contexts, aligning with ATT&CK technique T1203 for Exploitation for Credential Access and T1566 for Phishing.
The remediation for CVE-2015-8508 requires updating Bugzilla installations to versions that include proper input sanitization for the dependency graph feature. All affected versions including 2.x, 3.x, 4.x before 4.2.16, 4.3.x and 4.4.x before 4.4.11, and 4.5.x and 5.0.x before 5.0.2 must be upgraded to their patched releases. Organizations should implement comprehensive input validation and output encoding mechanisms specifically for the showdependencygraph.cgi component, ensuring that all user-provided data including bug summaries undergo proper sanitization before being rendered in HTML contexts. The fix typically involves implementing proper HTML escaping for all dynamic content within the dependency graph visualization and could include additional measures such as Content Security Policy headers to further mitigate the risk of XSS exploitation. Security teams should also consider implementing web application firewalls or other protective measures to detect and block suspicious input patterns that may indicate attempts to exploit this vulnerability, particularly in environments where immediate patching is not feasible. This vulnerability highlights the importance of maintaining up-to-date software and proper input validation practices in web applications, particularly those handling user-generated content in visualization contexts.