CVE-2017-9509 in Crucible
Summary
by MITRE
The review file upload resource in Atlassian Crucible before version 4.4.1 allows remote attackers to inject arbitrary HTML or JavaScript via a cross site scripting (XSS) vulnerability through the charset of a previously uploaded file.
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Analysis
by VulDB Data Team • 08/25/2023
The vulnerability identified as CVE-2017-9509 represents a critical cross site scripting flaw in Atlassian Crucible software prior to version 4.4.1. This vulnerability exists within the review file upload functionality where the application fails to properly sanitize or validate the character encoding of uploaded files. The flaw allows remote attackers to execute malicious scripts in the context of a victim's browser by manipulating the charset parameter of previously uploaded files. This type of vulnerability falls under CWE-79 which specifically addresses cross site scripting flaws in software applications. The issue demonstrates how insecure input handling can create persistent security weaknesses that affect user interactions with the application.
The technical exploitation of this vulnerability occurs when an attacker uploads a file with a malicious charset declaration that contains embedded HTML or JavaScript code. When other users view the review containing this file, their browsers interpret the malicious content as legitimate, executing the injected scripts. The vulnerability is particularly dangerous because it leverages the existing file upload mechanism rather than requiring new attack vectors. This allows attackers to establish persistent XSS payloads that can capture user sessions, redirect traffic, or perform other malicious activities. The flaw operates at the application layer and requires no privileged access to exploit, making it particularly attractive to attackers seeking broad impact.
The operational impact of this vulnerability extends beyond simple script execution to encompass potential data theft, session hijacking, and privilege escalation within the application environment. Attackers could use the XSS capability to steal cookies, access sensitive review data, or manipulate user permissions within Crucible. The vulnerability affects all users who have access to the review functionality and can potentially compromise the entire application security posture. Organizations using affected versions of Crucible face significant risk of unauthorized access to code review processes, which could lead to intellectual property theft, security bypasses, or system compromise. This vulnerability aligns with ATT&CK technique T1059.007 which covers scripting languages and T1531 which addresses credential access through web application attacks.
Mitigation strategies for CVE-2017-9509 require immediate patching of Atlassian Crucible to version 4.4.1 or later where the vulnerability has been addressed. Organizations should also implement additional security controls including input validation for file uploads, character encoding normalization, and content security policies to prevent XSS execution. Network segmentation and monitoring should be enhanced to detect suspicious file upload activities and unusual charset declarations. Security teams should conduct thorough vulnerability assessments of all Atlassian products and review file upload configurations to ensure proper sanitization of user-provided data. The fix implemented by Atlassian addresses the core issue by properly handling charset parameters during file review processing, preventing the injection of malicious content through the upload mechanism.