CVE-2025-26776 in Chaty Pro Plugin
Summary
by MITRE • 02/22/2025
Unrestricted Upload of File with Dangerous Type vulnerability in NotFound Chaty Pro allows Upload a Web Shell to a Web Server. This issue affects Chaty Pro: from n/a through 3.3.3.
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Analysis
by VulDB Data Team • 02/22/2025
The vulnerability identified as CVE-2025-26776 represents a critical security flaw in the NotFound Chaty Pro application that enables unauthorized file upload capabilities with potentially malicious file types. This issue stems from inadequate input validation and sanitization mechanisms within the file upload functionality, creating an avenue for attackers to bypass security controls and execute arbitrary code on the affected web server. The vulnerability specifically impacts versions of Chaty Pro ranging from the initial release through version 3.3.3, indicating a persistent flaw that has remained unaddressed across multiple iterations of the software.
The technical implementation of this vulnerability resides in the application's file upload handler which fails to properly validate file extensions, content types, or file signatures before processing uploaded files. This unrestricted upload capability allows malicious actors to submit files with dangerous extensions such as .php, .asp, .jsp, or other server-side include formats that can execute code when accessed through the web server. The flaw directly maps to CWE-434, which describes the weakness of unrestricted upload of file with dangerous type, where applications fail to validate or restrict file uploads to only safe and expected formats. Attackers can leverage this vulnerability to upload web shells or other malicious payloads that provide persistent access to the compromised server environment.
The operational impact of this vulnerability is severe and far-reaching, as it enables remote code execution capabilities that can result in complete server compromise. Once an attacker successfully uploads a web shell, they gain the ability to execute arbitrary commands on the target system, potentially leading to data exfiltration, lateral movement within the network, and establishment of persistent backdoors. The vulnerability creates a direct pathway for attackers to escalate privileges and maintain access to the compromised environment without detection. This type of vulnerability aligns with ATT&CK technique T1190, which involves exploiting vulnerabilities in web applications to establish initial access and maintain persistence within target environments.
Mitigation strategies for CVE-2025-26776 must focus on implementing robust input validation, content type checking, and file extension filtering mechanisms. Organizations should immediately upgrade to the latest version of Chaty Pro where this vulnerability has been addressed through proper file validation controls. Additionally, implementing proper file upload restrictions including whitelisting of allowed file extensions, content type verification, and storing uploaded files outside the web root directory can significantly reduce the attack surface. Network segmentation and monitoring for suspicious file upload activities should also be implemented to detect and prevent exploitation attempts. The remediation process should include thorough security testing of the file upload functionality and implementation of proper access controls to limit upload capabilities to authorized users only.