CVE-2019-19704 in Upsource
Summary
by MITRE
In JetBrains Upsource before 2020.1, information disclosure is possible because of an incorrect user matching algorithm.
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Analysis
by VulDB Data Team • 08/09/2020
The vulnerability identified as CVE-2019-19704 affects JetBrains Upsource versions prior to 2020.1, representing a critical information disclosure flaw that stems from an incorrect user matching algorithm implementation. This vulnerability resides within the authentication and authorization mechanisms of the platform, where the flawed user matching logic creates opportunities for unauthorized access to sensitive information. The issue manifests when the system fails to properly validate user credentials or account associations, potentially allowing attackers to bypass normal access controls and gain visibility into data that should remain restricted to authorized personnel.
The technical root cause of this vulnerability can be categorized under CWE-287 which deals with improper authentication scenarios. The incorrect user matching algorithm likely involves flawed comparison functions or insufficient validation checks during the authentication process, enabling attackers to exploit mismatches in user identification logic. This type of vulnerability typically occurs when the system employs weak cryptographic functions, improper session management, or inadequate input validation during user verification processes. The flaw may involve predictable patterns in user identification, insufficient entropy in authentication tokens, or logical errors in access control decision-making algorithms.
From an operational perspective, this information disclosure vulnerability poses significant risks to organizations using JetBrains Upsource for code review and collaboration. Attackers who successfully exploit this flaw could potentially access confidential source code repositories, review comments, commit histories, and other sensitive project information that should be restricted to authorized team members. The impact extends beyond simple data exposure, as the vulnerability may enable lateral movement within the system, allowing attackers to escalate privileges or gain access to additional resources within the organization's development infrastructure. This vulnerability particularly affects development environments where source code confidentiality and access control are paramount for maintaining intellectual property protection and security posture.
Mitigation strategies for CVE-2019-19704 should prioritize immediate upgrade to JetBrains Upsource version 2020.1 or later, which contains the patched user matching algorithm. Organizations should also implement additional security controls including regular access reviews, monitoring for unusual authentication patterns, and enhanced logging of user access attempts. The remediation process should include thorough testing of the updated authentication mechanisms to ensure proper user matching functionality. Security teams should conduct vulnerability assessments to identify any potential exploitation attempts and implement network segmentation to limit the attack surface. Additionally, organizations should review their overall authentication architecture and consider implementing multi-factor authentication mechanisms to strengthen access controls beyond the basic username-password authentication that this vulnerability exploits. The ATT&CK framework categorizes this vulnerability under credential access and privilege escalation techniques, emphasizing the need for comprehensive defensive measures that address both the specific flaw and broader authentication security gaps.