CVE-2018-18257 in BageCMS
Summary
by MITRE
An issue was discovered in BageCMS 3.1.3. An attacker can delete any files and folders on the web server via an index.php?r=admini/template/batch&command=deleteFile&fileName= or index.php?r=admini/template/batch&command=deleteFolder&folderName=../ directory traversal URI.
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Analysis
by VulDB Data Team • 04/01/2020
This vulnerability exists in BageCMS version 3.1.3 and represents a critical directory traversal flaw that allows remote attackers to execute arbitrary file deletion operations on the affected web server. The vulnerability manifests through specific URI endpoints that accept user-supplied parameters without proper validation or sanitization, creating an opportunity for attackers to manipulate file paths and gain unauthorized access to the server's file system. The attack vector specifically targets the batch deletion functionality within the administrative template module, where the command parameter accepts deleteFile and deleteFolder operations.
The technical implementation of this vulnerability stems from inadequate input validation and path sanitization mechanisms within the application's file handling routines. When users submit requests through the affected URIs, the application processes the fileName and folderName parameters directly without implementing proper access controls or path validation checks. This allows attackers to craft malicious requests that include directory traversal sequences such as ../ to navigate outside the intended directory boundaries. The vulnerability is classified as a directory traversal attack pattern that aligns with CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory.
From an operational impact perspective, this vulnerability poses significant risks to the security and integrity of web applications running BageCMS 3.1.3. Attackers can leverage this flaw to delete critical system files, configuration files, or even executable code that could compromise the entire web application or underlying server. The ability to delete folders and files remotely means that attackers can potentially disrupt service availability, remove security patches, or eliminate evidence of compromise. This vulnerability can be exploited by attackers with minimal privileges and does not require authentication, making it particularly dangerous in environments where the administrative interface is accessible to unauthorized users.
The attack pattern associated with this vulnerability aligns with several tactics and techniques documented in the MITRE ATT&CK framework, particularly those related to privilege escalation and persistence mechanisms. An attacker who successfully exploits this vulnerability can establish a foothold in the system and potentially escalate privileges to gain broader access to network resources. The vulnerability also enables techniques for maintaining access through file deletion or modification, which can be used to cover tracks or establish backdoors. Organizations should consider this vulnerability as part of a broader attack surface assessment, as it can serve as a stepping stone for more sophisticated attacks that leverage additional weaknesses in the application architecture.
Mitigation strategies for this vulnerability should include immediate implementation of proper input validation and parameter sanitization mechanisms within the application code. Developers should enforce strict access controls and path validation that prevents directory traversal sequences from being processed as legitimate file paths. The recommended approach involves implementing a whitelist-based validation system that only accepts predefined safe file paths and rejects any input containing traversal sequences. Additionally, organizations should ensure that administrative interfaces are properly secured with strong authentication mechanisms and network segmentation to limit exposure to unauthorized users. Regular security updates and patch management procedures should be implemented to address similar vulnerabilities that may exist in other components of the web application stack.