CVE-2017-18095 in Crucible
Summary
by MITRE
The SnippetRPCServiceImpl class in Atlassian Crucible before version 4.5.1 (the fixed version 4.5.x) and before 4.6.0 allows remote attackers to comment on snippets they do not have authorization to access via an improper authorization vulnerability.
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Analysis
by VulDB Data Team • 01/06/2020
The vulnerability identified as CVE-2017-18095 represents a critical authorization flaw within Atlassian Crucible's SnippetRPCServiceImpl component that affects versions prior to 4.5.1 and 4.6.0. This issue stems from inadequate access control mechanisms that permit unauthorized users to interact with code snippets they should not be permitted to access. The flaw exists in the remote procedure call implementation that handles snippet operations, specifically allowing malicious actors to submit comments on restricted code segments without proper authentication or authorization validation.
The technical exploitation of this vulnerability occurs through the improper authorization checks implemented in the SnippetRPCServiceImpl class. Attackers can leverage this weakness to bypass normal access controls and post comments on code snippets that are protected by access restrictions. This authorization bypass enables threat actors to inject malicious content into restricted code repositories, potentially leading to information disclosure or the introduction of harmful comments that could mislead developers about the security posture of the code. The vulnerability aligns with CWE-285, which addresses improper authorization in software systems, and represents a classic case of insufficient access control validation.
The operational impact of this vulnerability extends beyond simple unauthorized access to include potential information leakage and the ability to manipulate code review processes. An attacker with access to the system can comment on sensitive code snippets, potentially introducing misleading information or attempting to obscure legitimate security concerns. This capability undermines the integrity of the code review process and could be exploited to hide malicious activities within the codebase. The vulnerability also creates a persistent threat vector that remains active as long as affected versions remain in use, potentially allowing attackers to establish footholds within development environments.
Organizations affected by this vulnerability should immediately implement mitigations including upgrading to Atlassian Crucible versions 4.5.1 or 4.6.0, which contain the necessary authorization fixes. Additional defensive measures should include monitoring for unauthorized comment activity on code snippets and implementing network segmentation to limit access to development environments. The vulnerability demonstrates the importance of proper access control implementation in web services and aligns with ATT&CK technique T1078 which covers legitimate credentials usage and privilege escalation. Security teams should also consider implementing automated scanning tools to detect similar authorization flaws in other applications and establish robust patch management processes to ensure timely remediation of such vulnerabilities.