CVE-2019-15516 in Cuberite
Summary
by MITRE
Cuberite before 2019-06-11 allows webadmin directory traversal via ....// because the protection mechanism simply removes one ../ substring.
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Analysis
by VulDB Data Team • 12/01/2023
The vulnerability identified as CVE-2019-15516 affects the Cuberite Minecraft server software version prior to the 2019-06-11 release. This represents a critical directory traversal flaw that undermines the security mechanisms designed to protect the webadmin interface. The vulnerability specifically targets the protection mechanism implemented to prevent unauthorized access to server files through malicious path manipulation attempts. The flaw stems from an overly simplistic approach to path sanitization where the system merely removes a single instance of the "../" sequence from user input, rather than implementing comprehensive validation of the entire file path.
The technical implementation of this vulnerability exploits the inadequate sanitization logic within the webadmin component of Cuberite. When a user submits a path containing directory traversal sequences, the software's protection mechanism fails to account for multiple consecutive traversal attempts. This allows an attacker to bypass the intended security controls by crafting malicious input strings that contain multiple "../" sequences, where only the first occurrence gets removed. The resulting path manipulation enables access to files and directories outside the intended webadmin scope, potentially exposing sensitive server data, configuration files, and system resources to unauthorized access.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates a potential attack vector for more sophisticated exploitation attempts. An attacker could leverage this weakness to access server configuration files, user data, or even execute arbitrary code if the system allows file inclusion from traversed paths. The vulnerability directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as directory traversal or path traversal attacks. This weakness represents a fundamental flaw in input validation and access control implementation within the application's web interface.
Security practitioners should recognize this vulnerability as a clear example of inadequate input sanitization and the dangers of relying on simple string replacement mechanisms for security purposes. The attack surface includes not only the webadmin interface but potentially any component that processes user-supplied file paths without proper validation. Organizations running affected Cuberite installations should immediately apply the patch released on June 11, 2019, which implements proper path validation and normalization techniques. The remediation process should also include reviewing all web interfaces for similar path traversal vulnerabilities and implementing comprehensive input validation that considers the entire path structure rather than simple substring removal. This vulnerability aligns with ATT&CK technique T1059, which involves the execution of commands through web interfaces, and demonstrates the importance of robust access control mechanisms in preventing unauthorized system access.