CVE-2015-8398 in Confluence
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Atlassian Confluence before 5.8.17 allows remote attackers to inject arbitrary web script or HTML via the PATH_INFO to rest/prototype/1/session/check.
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Analysis
by VulDB Data Team • 07/24/2025
The CVE-2015-8398 vulnerability represents a critical cross-site scripting flaw discovered in Atlassian Confluence versions prior to 5.8.17. This vulnerability exists within the application's handling of HTTP PATH_INFO parameters when processing requests to the rest/prototype/1/session/check endpoint. The flaw enables remote attackers to execute malicious scripts in the context of a victim's browser, potentially leading to unauthorized actions and data theft. The vulnerability specifically affects the REST API prototype endpoint which is used for session validation and authentication checks within the Confluence platform. This type of vulnerability falls under CWE-79 - Improper Neutralization of Input During Web Page Generation, which is a fundamental weakness in web application security that allows malicious input to be interpreted as executable code.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious URL containing script code within the PATH_INFO parameter and submits it to the vulnerable Confluence instance. The application fails to properly sanitize or escape the input before rendering it in the web response, allowing the injected script to execute in the victim's browser context. This particular endpoint is designed to check session validity and authentication status, making it an attractive target for attackers seeking to escalate privileges or hijack user sessions. The vulnerability demonstrates poor input validation practices and inadequate output encoding mechanisms that are essential for preventing XSS attacks. According to ATT&CK framework, this vulnerability maps to T1059.008 - Command and Scripting Interpreter: PowerShell, as it allows attackers to execute malicious scripts in the browser environment, and T1566.001 - Credential Access: Phishing, since it can be used to steal session cookies and credentials.
The operational impact of CVE-2015-8398 is significant for organizations using vulnerable Confluence instances, as it provides attackers with a straightforward method to compromise user accounts and potentially gain unauthorized access to sensitive corporate documentation. Attackers can leverage this vulnerability to perform session hijacking, steal user credentials, redirect users to malicious sites, or execute arbitrary commands within the context of authenticated sessions. The vulnerability affects both legitimate users and administrators, creating a potential pathway for attackers to escalate privileges and access restricted content. Organizations with Confluence instances that have not been updated to version 5.8.17 or later remain at risk, particularly those with less sophisticated security monitoring capabilities. The vulnerability also impacts compliance requirements for data protection and information security, as it creates an attack vector that can lead to unauthorized data access and potential regulatory violations.
Organizations should immediately implement mitigations including updating to Atlassian Confluence version 5.8.17 or later, which contains the necessary patches to address this vulnerability. Network administrators should also consider implementing web application firewalls that can detect and block malicious PATH_INFO patterns, and security teams should conduct thorough vulnerability assessments to identify any other potentially affected systems. Additional protective measures include implementing Content Security Policy headers to limit script execution, disabling unnecessary REST API endpoints when not required, and monitoring for suspicious URL patterns in web server logs. The vulnerability highlights the importance of maintaining up-to-date software versions and implementing robust input validation controls across all web applications. Organizations should also consider implementing automated patch management processes to ensure timely deployment of security updates and maintain visibility into their application security posture through regular security assessments and penetration testing activities.