CVE-2016-10716 in Calendar Plugin
Summary
by MITRE
The Mail.ru Calendar plugin before 2.5.0.61 for Atlassian Jira has XSS via the Name field in a Create Calender action, related to a MailRuCalendar.jspa#period/month URI.
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Analysis
by VulDB Data Team • 02/22/2023
The vulnerability identified as CVE-2016-10716 affects the Mail.ru Calendar plugin for Atlassian Jira, specifically versions prior to 2.5.0.61. This issue represents a cross-site scripting vulnerability that allows attackers to inject malicious scripts into the application through user-controlled input fields. The vulnerability manifests when users create calendar events through the Mail.ru Calendar plugin, specifically targeting the Name field within the Create Calendar action functionality. The attack vector is particularly concerning as it leverages a URI pattern that includes MailRuCalendar.jspa#period/month, indicating the vulnerability exists within the plugin's calendar management interface.
The technical flaw stems from insufficient input validation and output encoding within the plugin's handling of user-supplied data in the Name field. When users enter data into this field during calendar event creation, the application fails to properly sanitize or encode the input before rendering it in the web page context. This allows malicious actors to inject HTML or JavaScript code that executes in the context of other users' browsers who view the affected calendar entries. The vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws in web applications, where improper validation of user input leads to arbitrary code execution in victim browsers. The attack requires minimal privileges as it exploits the plugin's calendar creation functionality that is typically accessible to regular users within the Jira environment.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform various malicious activities including session hijacking, data theft, privilege escalation, and redirection to malicious websites. An attacker who successfully exploits this vulnerability could steal session cookies from authenticated users, potentially gaining unauthorized access to Jira instances with elevated privileges. The vulnerability also enables the execution of malicious scripts that could exfiltrate sensitive project data, modify calendar entries, or even redirect users to phishing sites that mimic legitimate Jira interfaces. Given that Jira is commonly used for project management and issue tracking in enterprise environments, the compromise of calendar functionality could lead to broader security implications affecting multiple users and projects within the organization.
Mitigation strategies for this vulnerability should focus on immediate patching of the Mail.ru Calendar plugin to version 2.5.0.61 or later, which contains the necessary fixes for input validation and output encoding. Organizations should also implement additional defensive measures including web application firewall rules to detect and block suspicious script patterns in calendar-related requests, enhanced input validation at the application level, and regular security scanning of installed plugins. The remediation process should include thorough testing of the updated plugin to ensure compatibility with existing Jira configurations and workflows. Security teams should also monitor for any signs of exploitation attempts and consider implementing security awareness training for users who interact with calendar functionality. From an ATT&CK framework perspective, this vulnerability aligns with T1059.007 for script execution and T1566 for credential access, making it a significant concern for organizations that rely on Jira for their development and project management processes.