CVE-2019-9889 in Vanilla
Summary
by MITRE
In Vanilla before 2.6.4, a flaw exists within the getSingleIndex function of the AddonManager class. The issue results in a require call using a crafted type value, leading to Directory Traversal with File Inclusion. An attacker can leverage this vulnerability to execute code under the context of the web server.
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Analysis
by VulDB Data Team • 08/04/2023
The vulnerability identified as CVE-2019-9889 affects Vanilla forums software versions prior to 2.6.4, specifically within the AddonManager class where the getSingleIndex function contains a critical security flaw. This vulnerability represents a directory traversal attack vector that enables remote code execution through improper input validation and handling of user-supplied data. The flaw exists in how the software processes addon index requests, creating an opportunity for malicious actors to manipulate the system's file inclusion mechanisms.
The technical implementation of this vulnerability stems from the improper sanitization of input parameters within the getSingleIndex function, which directly influences the require call mechanism. When an attacker supplies a crafted type value, the system fails to properly validate or escape the input before using it in a file inclusion context. This creates a directory traversal condition where the attacker can manipulate the file path to access arbitrary files on the server filesystem. The vulnerability operates under CWE-22, which defines directory traversal flaws, and specifically aligns with CWE-94, representing improper control of generation of code, as the crafted input leads to unauthorized code execution. The ATT&CK framework categorizes this under T1059.007 for command and scripting interpreter and T1566 for malicious file execution.
The operational impact of this vulnerability is severe as it allows remote attackers to execute arbitrary code with the privileges of the web server process, potentially leading to complete system compromise. An attacker can leverage this vulnerability to read sensitive files, upload malicious payloads, establish persistent access, or use the compromised server as a pivot point for further attacks within the network. The vulnerability affects the confidentiality, integrity, and availability of the affected system, making it a critical threat to any organization relying on Vanilla forums for community management or content sharing. The attack surface expands significantly as the vulnerability can be exploited through web-based interfaces without requiring prior authentication, making it particularly dangerous for publicly accessible installations.
Mitigation strategies for this vulnerability include immediate patching to version 2.6.4 or later, which addresses the input validation flaws in the AddonManager class. Organizations should implement proper input sanitization and validation mechanisms, particularly for user-supplied parameters used in file operations. Network segmentation and access controls should be enforced to limit exposure of the affected system, while monitoring for unusual file access patterns or code execution attempts should be implemented. Security headers and web application firewalls can provide additional layers of protection, though the most effective defense remains the immediate application of the vendor-provided security patch. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in other components of the system architecture.