CVE-2017-18034 in FishEye
Summary
by MITRE
The source browse resource in Atlassian FishEye and Crucible before version 4.5.1 and 4.6.0 allows allows remote attackers that have write access to an indexed repository to inject arbitrary HTML or JavaScript via a cross site scripting (XSS) vulnerability in via a specially crafted repository branch name when trying to display deleted files of the branch.
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Analysis
by VulDB Data Team • 01/01/2020
The vulnerability identified as CVE-2017-18034 represents a critical cross site scripting flaw within Atlassian FishEye and Crucible platforms, specifically affecting versions prior to 4.5.1 and 4.6.0. This security weakness resides in the source browse resource functionality that handles repository branch names, creating a pathway for malicious actors to execute arbitrary code through crafted input. The vulnerability emerges when the system attempts to display deleted files associated with a specially constructed repository branch name, allowing attackers with write permissions to the indexed repository to inject malicious scripts that persist in the application's user interface.
The technical exploitation of this vulnerability stems from insufficient input validation and output encoding within the source browsing component of FishEye and Crucible. When a repository branch name contains malicious payload characters, the system fails to properly sanitize this input before rendering it in the user interface context where deleted file information is displayed. This failure creates an environment where HTML and JavaScript code can be executed within the browser context of authenticated users who view the affected branch information, effectively bypassing standard security controls and session management mechanisms.
The operational impact of this vulnerability extends beyond simple script execution, as it enables attackers with write access to repositories to potentially escalate their privileges or compromise user sessions. Attackers can craft branch names containing malicious scripts that execute when legitimate users browse repository contents, potentially stealing session cookies, redirecting users to malicious sites, or performing actions on behalf of the compromised user. The vulnerability particularly affects environments where multiple users collaborate on repositories, as the malicious code execution can occur silently in the background when users navigate to affected branches, making detection challenging and potentially allowing for prolonged unauthorized access.
Organizations using affected versions of FishEye and Crucible face significant security risks, including potential data exfiltration, session hijacking, and persistent backdoor access through the executed malicious scripts. The vulnerability aligns with CWE-79, which describes cross site scripting flaws in web applications, and maps to ATT&CK technique T1059.007 for scripting languages, specifically targeting the execution of malicious JavaScript within user browsers. Security teams should prioritize immediate patching of affected systems, implementing additional monitoring for suspicious branch naming patterns, and conducting thorough security assessments of repository access controls to prevent unauthorized write access that could enable exploitation of this vulnerability.