CVE-2019-20106 in JIRA Server
Summary
by MITRE
Comment properties in Atlassian Jira Server and Data Center before version 7.13.12, from 8.0.0 before version 8.5.4, and 8.6.0 before version 8.6.1 allows remote attackers to make comments on a ticket to which they do not have commenting permissions via a broken access control bug.
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Analysis
by VulDB Data Team • 03/28/2024
The vulnerability identified as CVE-2019-20106 represents a critical access control flaw within Atlassian Jira Server and Data Center platforms across multiple version ranges. This security weakness stems from improper validation of user permissions when processing comment requests, allowing unauthorized individuals to bypass established access controls and post comments on tickets they should not be able to modify. The flaw affects versions prior to 7.13.12 for the 7.x series, versions prior to 8.5.4 for the 8.0.x series, and versions prior to 8.6.1 for the 8.6.0 series, creating a substantial attack surface across multiple product releases.
The technical implementation of this vulnerability resides in the comment processing logic where the system fails to properly verify user authorization before accepting and storing comment data. When a user submits a comment through the Jira interface or API, the application should validate that the requesting user possesses the necessary permissions to comment on the specific issue or ticket. However, the broken access control mechanism allows attackers to manipulate request parameters or exploit inconsistencies in permission checking, effectively granting them commenting privileges on restricted tickets. This flaw operates at the application level and can be exploited through both web interfaces and programmatic API calls, making it particularly dangerous for organizations that rely heavily on Jira's issue tracking and collaboration features.
The operational impact of this vulnerability extends beyond simple unauthorized comment posting, as it represents a fundamental breakdown in the application's security model that could potentially enable more sophisticated attacks. Attackers with access to the system could exploit this vulnerability to post misleading information, insert malicious links, or manipulate the audit trail of critical business processes. The vulnerability could be leveraged to compromise the integrity of issue tracking workflows, potentially leading to confusion in incident response procedures, misdirection of development efforts, or even social engineering attacks where malicious comments could be used to manipulate team members. Organizations relying on Jira for sensitive project management, security incident tracking, or compliance reporting face significant risks from this access control bypass.
Organizations should immediately implement mitigations including upgrading to the patched versions mentioned in the advisory, specifically versions 7.13.12, 8.5.4, and 8.6.1 respectively. Additionally, administrators should review and audit existing comment permissions to ensure that unauthorized users cannot post comments on sensitive tickets. Network segmentation and monitoring of comment-related API endpoints can help detect potential exploitation attempts. This vulnerability aligns with CWE-285, which addresses improper authorization in software systems, and maps to ATT&CK technique T1078 which covers valid accounts and legitimate credentials as a means of bypassing access controls. The flaw demonstrates the critical importance of proper input validation and authorization checks in web applications, particularly those handling sensitive business data and collaborative workflows.