CVE-2019-12901 in Cells
Summary
by MITRE
Pydio Cells before 1.5.0 fails to neutralize '../' elements, allowing an attacker with minimum privilege to Upload files to, and Delete files/folders from, an unprivileged directory, leading to Privilege escalation.
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Analysis
by VulDB Data Team • 10/06/2023
CVE-2019-12901 represents a critical path traversal vulnerability within Pydio Cells versions prior to 1.5.0 that fundamentally undermines the application's file system access controls and privilege management mechanisms. This vulnerability resides in the application's handling of file path operations where it fails to properly sanitize or neutralize '../' sequences in file upload and deletion operations. The flaw allows authenticated users with minimal privileges to manipulate file system paths through crafted input that includes directory traversal sequences, effectively bypassing intended access restrictions. The vulnerability operates at the core of the application's file management functionality, specifically affecting how the system processes relative path references during file operations.
The technical implementation of this vulnerability stems from insufficient input validation and sanitization within the file system interaction components of Pydio Cells. When users upload or delete files, the application processes user-supplied paths without adequately stripping or neutralizing directory traversal sequences that could allow access to restricted directories outside the intended operational scope. This weakness creates a direct pathway for privilege escalation as attackers can leverage these traversal sequences to access and manipulate files in directories that should be restricted to higher privilege users. The vulnerability specifically affects the application's ability to properly resolve and validate file paths, enabling attackers to navigate beyond the intended file system boundaries.
The operational impact of this vulnerability extends far beyond simple file access manipulation, as it enables a range of malicious activities that can compromise system integrity and data confidentiality. An attacker with minimal privileges can upload malicious files to unprivileged directories, potentially executing code or establishing persistence mechanisms within the application environment. Additionally, the ability to delete files and folders from restricted locations can lead to data destruction, service disruption, and further escalation opportunities within the compromised system. This vulnerability effectively undermines the principle of least privilege by allowing unauthorized access to system resources that should remain protected from lower-privilege users. The risk is particularly severe in environments where Pydio Cells serves as a collaborative file sharing platform with multiple user roles and access levels.
Organizations affected by this vulnerability should prioritize immediate remediation through the application of the official 1.5.0 patch or subsequent versions that address the path traversal flaw. The mitigation strategy must include comprehensive testing of file upload and deletion operations to ensure that all path traversal sequences are properly neutralized before any file system operations are executed. Security teams should implement additional monitoring of file system access patterns and establish alerts for unusual file creation or deletion activities that might indicate exploitation attempts. The vulnerability aligns with CWE-22 Path Traversal and CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component, and represents a clear violation of the principle of input validation and access control enforcement. From an ATT&CK framework perspective, this vulnerability maps to T1059 Command and Scripting Interpreter and T1078 Valid Accounts, as it enables attackers to escalate privileges and maintain access through manipulated file system operations, potentially leading to broader system compromise and data exfiltration capabilities.