CVE-2017-18094 in FishEye
Summary
by MITRE
Various resources in Atlassian Fisheye and Crucible before version 4.4.3 (the fixed version for 4.4.x) and 4.5.0 allow remote attackers with administrative privileges to inject arbitrary HTML or JavaScript via a cross site scripting (XSS) vulnerability through the base path setting of a configured file system repository.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 01/15/2020
The vulnerability CVE-2017-18094 represents a critical cross site scripting flaw in Atlassian Fisheye and Crucible software versions prior to 4.4.3 and 4.5.0 respectively. This security weakness resides within the base path setting configuration of file system repositories, where administrative users can inadvertently introduce malicious code through seemingly legitimate configuration parameters. The flaw enables remote attackers to execute arbitrary HTML or JavaScript code within the context of the victim's browser, potentially compromising user sessions and data integrity. The vulnerability specifically targets the administrative interface components where repository settings are managed, making it particularly dangerous as it requires only administrative access to exploit, which is typically limited to authorized personnel within organizations.
The technical implementation of this XSS vulnerability stems from insufficient input validation and output encoding within the application's configuration handling mechanisms. When administrators configure file system repositories through the web interface, the base path parameter fails to properly sanitize user-supplied input before rendering it back to the browser. This creates an environment where malicious payloads can be injected and subsequently executed when other users view the affected configuration pages. The vulnerability manifests as a classic reflected XSS issue where the malicious input is processed by the server and immediately reflected back to the user's browser without adequate sanitization. The CWE-79 classification applies here as the vulnerability represents a failure to properly encode output data, allowing malicious scripts to be executed in the context of the user's browser session.
The operational impact of this vulnerability extends beyond simple code injection, potentially enabling attackers to escalate privileges, steal session cookies, perform actions on behalf of authenticated users, and access sensitive repository information. Given that administrative access is required to exploit this flaw, it represents a significant risk to organizations that maintain extensive code repositories and collaborative development environments. Attackers could leverage this vulnerability to gain unauthorized access to source code, modify repository configurations, or redirect users to malicious websites. The attack vector is particularly concerning as it operates through legitimate administrative functions, making it difficult to detect through standard security monitoring. Organizations using these applications may experience unauthorized data access, potential code tampering, and compromise of development workflows. The vulnerability also aligns with ATT&CK technique T1059.007 for scripting languages, as attackers can execute JavaScript payloads to manipulate the application behavior and potentially establish persistent access.
Mitigation strategies for this vulnerability require immediate patching to versions 4.4.3 and 4.5.0 respectively, which address the input validation and output encoding deficiencies. Organizations should also implement additional security controls such as restricting administrative access to trusted users only, implementing network segmentation to limit exposure, and conducting regular security assessments of administrative interfaces. The principle of least privilege should be enforced by ensuring that administrative accounts have minimal necessary permissions, and multi-factor authentication should be implemented for all administrative access points. Regular security monitoring and log analysis should be enhanced to detect unusual administrative activities that might indicate exploitation attempts. Additionally, organizations should consider implementing web application firewalls to detect and block suspicious input patterns that could indicate XSS attack attempts. The vulnerability highlights the importance of proper input sanitization and output encoding practices in web applications, particularly in administrative interfaces where the potential impact of exploitation is highest.