CVE-2023-49802 in LinkedCustomFields
Summary
by MITRE • 12/12/2023
The LinkedCustomFields plugin for MantisBT allows users to link values between two custom fields, creating linked drop-downs. Prior to version 2.0.1, cross-site scripting in the MantisBT LinkedCustomFields plugin allows Javascript execution, when a crafted Custom Field is linked via the plugin and displayed when reporting a new Issue or editing an existing one. This issue is fixed in version 2.0.1. As a workaround, one may utilize MantisBT's default Content Security Policy, which blocks script execution.
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Analysis
by VulDB Data Team • 01/02/2024
The CVE-2023-49802 vulnerability affects the LinkedCustomFields plugin for MantisBT, a widely used bug tracking system that enables users to create linked custom fields for enhanced data relationships. This particular plugin functionality allows administrators to establish dependencies between custom fields, creating dynamic drop-down menus that automatically update based on selections in related fields. The vulnerability stems from insufficient input validation and output sanitization within the plugin's rendering logic, specifically when displaying linked custom field values during issue creation or modification processes. Prior to version 2.0.1, the plugin failed to properly escape or sanitize user-provided data that was subsequently rendered in web pages, creating a path for malicious actors to inject and execute arbitrary javascript code within the context of authenticated users' browsers.
The technical flaw manifests through a classic cross-site scripting vulnerability categorized under CWE-79, which occurs when the plugin fails to properly sanitize user input before incorporating it into dynamic web content. When a malicious user creates a custom field containing javascript payload within its value, and this field is subsequently linked to another field through the plugin's functionality, the malicious script executes whenever the linked field values are displayed during issue reporting or editing operations. This vulnerability operates at the application layer and specifically targets the web interface rendering components of MantisBT, making it particularly dangerous as it requires no privileged access beyond standard user permissions to exploit. The attack vector leverages the legitimate plugin functionality to deliver malicious payloads, making detection more challenging as the malicious code appears to originate from trusted plugin components rather than external sources.
The operational impact of CVE-2023-49802 extends beyond simple script execution, as it enables attackers to perform a range of malicious activities within the context of authenticated users' sessions. Attackers could potentially steal session cookies, redirect users to malicious sites, modify displayed data, or even execute more sophisticated attacks such as credential theft or privilege escalation within the MantisBT environment. The vulnerability affects all users who have access to create or edit issues, making it particularly concerning for organizations with large user bases or those with less strict access controls. Given that the plugin is commonly used for creating complex issue tracking workflows, the attack surface is expanded beyond simple reporting to include all areas where custom fields are utilized, potentially affecting numerous business processes that depend on the integrity of these data relationships.
Organizations should immediately upgrade to MantisBT version 2.0.1 or later to remediate this vulnerability, as the fix implements proper input sanitization and output encoding mechanisms that prevent javascript execution in rendered custom field values. The recommended mitigation strategy involves not only applying the official patch but also implementing additional security measures such as reviewing and strengthening access controls, monitoring for suspicious custom field creation activities, and conducting regular security audits of plugin configurations. As a temporary workaround, administrators can enable MantisBT's default Content Security Policy which provides additional protection against script execution, though this should not be considered a permanent solution. The vulnerability also highlights the importance of proper security testing for third-party plugins and maintaining up-to-date software versions, aligning with ATT&CK technique T1211 for exploitation of vulnerabilities in web applications and emphasizing the need for defense in depth strategies in software development and deployment environments.