CVE-2026-33739 in fogproject
Summary
by MITRE • 03/27/2026
FOG is a free open-source cloning/imaging/rescue suite/inventory management system. Prior to 1.5.10.1812, the listing tables on multiple management pages (Host, Storage, Group, Image, Printer, Snapin) are vulnerable to Stored Cross-Site Scripting (XSS), due to insufficient server-side parameter sanitization in record creations/updates and a lack of HTML escaping in listing tables. Version 1.5.10.1812 patches the issue.
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Analysis
by VulDB Data Team • 03/27/2026
The vulnerability identified as CVE-2026-33739 affects FOG, a widely-used open-source system designed for cloning, imaging, rescue operations, and inventory management within enterprise environments. This critical security flaw exists in versions prior to 1.5.10.1812 and represents a stored cross-site scripting vulnerability that can be exploited by malicious actors to compromise system integrity and user sessions. The vulnerability specifically targets multiple management pages including Host, Storage, Group, Image, Printer, and Snapin interfaces where user data is displayed in listing tables. The flaw stems from inadequate server-side input validation mechanisms that fail to properly sanitize user-supplied parameters during record creation and update operations, combined with insufficient HTML escaping practices in the display layers of these management interfaces. This combination creates a persistent XSS vector that allows attackers to inject malicious scripts into the system's data storage, which then executes whenever authorized users view the affected listing tables.
The technical implementation of this vulnerability follows the CWE-79 pattern for cross-site scripting, specifically manifesting as a stored XSS variant where malicious payloads are permanently stored on the server and subsequently served to unsuspecting users. Attackers can exploit this by creating or modifying records through legitimate administrative functions with malicious script content embedded in fields such as hostnames, storage names, group descriptions, or other editable parameters. When authenticated users navigate to the affected management pages, their browsers execute the stored malicious scripts within their security context, potentially leading to session hijacking, credential theft, or further compromise of the underlying system. The vulnerability is particularly dangerous in enterprise environments where FOG systems manage critical infrastructure data, as it can be leveraged to gain unauthorized access to sensitive inventory information, system configurations, and user data.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform privilege escalation attacks and maintain persistent access to the FOG management system. According to ATT&CK framework techniques, this vulnerability maps to T1566.001 (Phishing: Spearphishing Attachment) and T1059.001 (Command and Scripting Interpreter: PowerShell) through the potential for attackers to establish malicious command execution capabilities. The stored nature of the XSS payload means that the vulnerability remains active even after initial exploitation, allowing attackers to maintain access over extended periods. Additionally, the impact on system availability and data integrity is significant, as compromised management interfaces could lead to unauthorized system modifications, data exfiltration, or complete system compromise. Organizations using FOG systems without the patch are particularly vulnerable due to the widespread adoption of this platform in enterprise environments where system administrators regularly interact with these management interfaces.
The remediation for CVE-2026-33739 is straightforward and involves upgrading to version 1.5.10.1812 or later, which implements proper input sanitization and HTML escaping mechanisms. Security administrators should immediately implement this patch across all affected systems and conduct thorough vulnerability assessments to identify any potential exploitation attempts. Organizations should also implement additional monitoring for suspicious activities in management interface logs and consider implementing web application firewalls to detect and block malicious script injection attempts. The patch addresses the root cause by ensuring that all user-supplied data undergoes proper sanitization before storage and that all output displayed in listing tables is properly escaped to prevent script execution. This vulnerability underscores the critical importance of input validation and output encoding practices in web applications, particularly those handling sensitive system management data, and serves as a reminder of the necessity for regular security updates in open-source software environments where security patches may not be automatically deployed.