CVE-2023-51647 in Allegra
Summary
by MITRE • 11/22/2024
Allegra saveInlineEdit Directory Traversal Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Allegra. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed.
The specific flaw exists within the saveInlineEdit method. The issue results from the lack of proper validation of a user-supplied path prior to using it in file operations. An attacker can leverage this vulnerability to execute code in the context of LOCAL SERVICE. Was ZDI-CAN-22528.
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Analysis
by VulDB Data Team • 01/04/2025
The CVE-2023-51647 vulnerability represents a critical directory traversal flaw in the Allegra application that enables remote code execution through improper input validation in the saveInlineEdit method. This vulnerability operates under the CWE-22 principle of directory traversal attacks, where user-supplied input is not properly sanitized before being used in file system operations. The flaw specifically manifests when the application processes inline edit requests without adequate validation of file paths, creating an opportunity for attackers to manipulate the system's file operations through crafted input sequences. Security researchers identified this weakness as a significant risk because it allows attackers to traverse directory structures and potentially access or modify files outside the intended application scope.
The technical implementation of this vulnerability demonstrates how insufficient input validation creates a pathway for malicious code execution within the application's operational context. When the saveInlineEdit method processes user requests, it fails to validate or sanitize the file path parameter, allowing an attacker to inject directory traversal sequences such as "../" or similar constructs. This weakness enables an attacker to manipulate file operations to target system files or directories that should remain protected. The vulnerability operates at the application layer where the system processes user inputs, making it particularly dangerous because it can be exploited through standard web application interfaces without requiring elevated privileges initially. The existing authentication mechanism, while present, can be bypassed, reducing the barrier to exploitation and making this vulnerability more accessible to threat actors.
The operational impact of CVE-2023-51647 is substantial as it allows remote attackers to execute arbitrary code with the privileges of the LOCAL SERVICE account, which typically has limited but system-level access. This privilege level provides attackers with the ability to modify application files, potentially leading to further privilege escalation or system compromise. The vulnerability's exploitation requires authentication, but the bypass capability means that attackers can potentially gain access through various means including credential theft, social engineering, or other authentication bypass techniques. The attack surface extends beyond simple code execution to include potential data exfiltration, system disruption, and establishment of persistent access points within the affected environment. Organizations running Allegra applications face significant risk as this vulnerability can be exploited from remote locations without requiring physical access to the system.
Mitigation strategies for CVE-2023-51647 should focus on implementing proper input validation and sanitization mechanisms within the saveInlineEdit method to prevent directory traversal attacks. The most effective approach involves implementing strict path validation that rejects any input containing traversal sequences or attempting to access parent directories. Organizations should also consider implementing additional security controls such as privilege separation, where the application runs with minimal required permissions rather than LOCAL SERVICE privileges. Network-level protections including firewalls and intrusion detection systems can help monitor for suspicious file path patterns, while application-level security measures should include regular security assessments and code reviews to identify similar vulnerabilities. The ATT&CK framework categorizes this vulnerability under T1059.001 for command and scripting interpreter and T1566.001 for spearphishing attachment, indicating that exploitation often involves executing malicious code through compromised applications. Organizations should also implement regular patch management procedures to ensure timely updates and remediation of such vulnerabilities. The vulnerability's classification as a directory traversal attack aligns with common exploitation patterns found in web application security frameworks, emphasizing the need for comprehensive input validation across all file operation methods.