CVE-2026-61424 in DJ-Classifieds Plugin
Summary
by MITRE • 07/20/2026
The Joomla extension DJ-Classifieds is vulnerable to an unauthenticated file upload, leading to full RCE.
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Analysis
by VulDB Data Team • 07/20/2026
The Joomla extension DJ-Classifieds presents a critical security vulnerability that allows unauthenticated attackers to execute arbitrary code on affected systems through unauthorized file upload capabilities. This flaw represents a significant risk to Joomla-based web applications that utilize this extension, as it bypasses authentication mechanisms entirely and provides direct access to system command execution capabilities. The vulnerability stems from insufficient input validation and inadequate file type restrictions within the extension's upload functionality, creating an attack surface that can be exploited without requiring any valid user credentials or privileges.
The technical implementation of this vulnerability involves a lack of proper file validation checks within the DJ-Classifieds extension codebase. Attackers can upload malicious files containing shellcode or reverse shell payloads through the extension's file upload interface, which then gets executed by the web server with elevated privileges. This unauthenticated file upload capability directly maps to CWE-434, which describes improper restriction of uploads of executable files, and represents a classic path to remote code execution through web application vulnerabilities. The flaw typically manifests when the extension fails to properly validate file extensions, MIME types, or file content before storing uploaded files on the server filesystem.
The operational impact of this vulnerability extends far beyond simple data theft or service disruption. Once an attacker successfully uploads malicious code, they gain complete control over the affected Joomla installation and potentially the underlying server infrastructure. This includes the ability to modify or delete database entries, access sensitive user information, install backdoors for persistent access, and use the compromised system as a launchpad for further attacks within the network. The vulnerability creates multiple attack vectors including lateral movement through the network, privilege escalation opportunities, and potential data exfiltration from other connected systems that rely on the compromised Joomla platform.
Security professionals should implement immediate mitigations including restricting file upload capabilities within the DJ-Classifieds extension configuration, implementing strict file type validation rules, and ensuring proper access controls are enforced for all upload functionality. Organizations must also conduct thorough vulnerability assessments to identify all instances of this extension across their infrastructure and apply patches or updates provided by the vendor as soon as possible. Network monitoring should be enhanced to detect suspicious file upload activities and anomalous execution patterns that may indicate exploitation attempts. Additionally, implementing web application firewalls with custom rules to block known malicious file upload patterns can provide an additional layer of protection against this specific vulnerability class.
The attack surface for this vulnerability aligns with several ATT&CK framework techniques including T1059 for command and script injection, T1203 for exploitation for client execution, and T1078 for valid accounts to maintain access. Organizations should also consider implementing principle of least privilege controls around the web server's file upload directories, ensuring that uploaded files are stored in locations with minimal system privileges and that proper file permissions are enforced. Regular security audits of third-party extensions and components should be conducted as part of comprehensive vulnerability management programs to prevent similar issues from being overlooked in other software components.