CVE-2020-4013 in FishEye
Summary
by MITRE
The review resource in Atlassian Fisheye and Crucible before version 4.8.1 allows remote attackers to inject arbitrary HTML or Javascript via a cross site scripting (XSS) vulnerability through the review objectives.
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Analysis
by VulDB Data Team • 06/02/2020
The vulnerability identified as CVE-2020-4013 represents a critical cross site scripting flaw within Atlassian Fisheye and Crucible platforms prior to version 4.8.1. This security weakness specifically affects the review resource functionality, which serves as a core component for code review processes within software development environments. The vulnerability arises from insufficient input validation and output encoding mechanisms that fail to properly sanitize user-supplied data before rendering it within web interfaces. Attackers can exploit this weakness by crafting malicious payloads within review objectives, which are then executed in the context of other users' browsers when they view the affected content.
The technical implementation of this XSS vulnerability stems from the application's failure to properly escape or filter special characters in review objective fields. When users submit review comments or objectives containing malicious script code, the system stores this data without adequate sanitization measures. The vulnerability falls under CWE-79 which specifically addresses Cross-Site Scripting flaws, and aligns with ATT&CK technique T1566.001 for initial access through spearphishing attachments or links. The flaw exists in the web application's user interface rendering logic where user-provided content is directly embedded into HTML responses without proper context-aware encoding. This allows attackers to inject malicious javascript code that executes in the victim's browser session, potentially leading to session hijacking, credential theft, or data exfiltration.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform authenticated actions on behalf of legitimate users within the Fisheye and Crucible environment. Since these platforms are commonly used for code review and collaboration in development teams, successful exploitation could compromise sensitive source code, development artifacts, and potentially provide attackers with access to underlying version control systems. The vulnerability affects organizations that rely on these tools for software development workflows, particularly those with less restrictive access controls or insufficient security monitoring. Attackers could leverage this weakness to escalate privileges, modify review comments, or redirect users to malicious sites, making it particularly dangerous in enterprise environments where code review processes are integral to security practices.
Organizations should immediately upgrade to Atlassian Fisheye and Crucible version 4.8.1 or later, which includes proper input validation and output encoding fixes for this vulnerability. Additional mitigations include implementing content security policies to restrict script execution, enabling web application firewalls to detect and block XSS payloads, and conducting regular security assessments of web applications. Security teams should also implement monitoring for suspicious review activity and user behavior patterns that might indicate exploitation attempts. The fix addresses the root cause by ensuring that all user-provided input is properly escaped and validated before being rendered in web contexts, preventing malicious code from executing in users' browsers. Organizations should also consider implementing automated security scanning tools to identify similar vulnerabilities in other web applications within their environment, as this type of flaw commonly occurs in development platforms and collaboration tools that handle user-generated content.