CVE-2019-8449 in JIRA
Summary
by MITRE
The /rest/api/latest/groupuserpicker resource in Jira before version 8.4.0 allows remote attackers to enumerate usernames via an information disclosure vulnerability.
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Analysis
by VulDB Data Team • 12/02/2024
The vulnerability identified as CVE-2019-8449 represents a critical information disclosure flaw within Atlassian Jira's REST API implementation. This vulnerability specifically affects the /rest/api/latest/groupuserpicker resource and exists in Jira versions prior to 8.4.0, making it a significant concern for organizations relying on older Jira installations. The flaw enables remote attackers to systematically enumerate valid usernames within the system, which constitutes a fundamental breach of information confidentiality and can serve as a precursor to more sophisticated attacks.
The technical nature of this vulnerability stems from insufficient access controls and input validation within the groupuserpicker API endpoint. When attackers make specific requests to this resource, the system inadvertently reveals information about user accounts without proper authentication or authorization checks. This occurs because the endpoint does not adequately verify whether the requesting user has legitimate access to view the enumerated user data, allowing unauthorized parties to discover valid usernames through iterative probing and response analysis. The vulnerability aligns with CWE-200, which categorizes information exposure vulnerabilities, and demonstrates how improper access control can lead to unauthorized information disclosure.
The operational impact of CVE-2019-8449 extends beyond simple username enumeration, as it provides attackers with valuable reconnaissance data that can facilitate subsequent attack phases. Once valid usernames are discovered, threat actors can employ password spraying, credential stuffing, or brute force attacks against these accounts, significantly increasing their chances of unauthorized system access. The vulnerability also enables social engineering campaigns where attackers can use the discovered usernames to craft more convincing phishing attempts or impersonation attacks. Additionally, the information disclosure can reveal organizational user structures and potentially expose sensitive information about system usage patterns and user roles within the Jira environment.
Organizations should prioritize immediate remediation of this vulnerability through the upgrade to Jira version 8.4.0 or later, which includes the necessary security patches and access control improvements. Network segmentation and firewall rules can provide temporary mitigation by restricting access to the affected REST API endpoints, particularly from untrusted networks. Implementing additional monitoring and logging around the groupuserpicker endpoint can help detect suspicious enumeration attempts and provide early warning of potential attacks. Security teams should also conduct comprehensive audits of their Jira configurations to ensure proper access controls and user permissions are in place, while considering the implementation of rate limiting and authentication controls for API endpoints. This vulnerability exemplifies the importance of maintaining up-to-date software versions and proper API security controls, as outlined in the ATT&CK framework's techniques for credential access and reconnaissance activities.