CVE-2020-13992 in Mods for HESK
Summary
by MITRE
An issue was discovered in Mods for HESK 3.1.0 through 2019.1.0. A Stored XSS issue allows remote unauthenticated attackers to abuse a helpdesk user's logged in session. A user with sufficient privileges to change their login-page image must open a crafted ticket.
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Analysis
by VulDB Data Team • 07/10/2020
The vulnerability CVE-2020-13992 represents a critical stored cross-site scripting flaw within the Mods for HESK (Helpdesk Enhancement Suite) software version range 3.1.0 through 2019.1.0. This security weakness enables remote attackers to exploit a helpdesk user's authenticated session without requiring prior authentication credentials, creating a significant risk for organizations relying on this helpdesk management system. The vulnerability specifically targets the login page image customization feature, which serves as an attack vector for executing malicious scripts within the context of a victim's session.
The technical implementation of this vulnerability stems from inadequate input validation and output sanitization within the Mods for HESK application. When administrators with sufficient privileges modify their login page image settings, the system fails to properly sanitize user-supplied input before storing and rendering it. This stored malicious content becomes executable when other users view the helpdesk interface, particularly when they open crafted tickets that trigger the rendering of the compromised login page image. The vulnerability operates under CWE-79 which categorizes cross-site scripting flaws as weaknesses in input validation and output encoding, and aligns with ATT&CK technique T1059.001 for command and scripting interpreter execution through web-based attacks.
The operational impact of this vulnerability extends beyond simple script execution, as it allows attackers to hijack authenticated sessions and potentially gain unauthorized access to sensitive helpdesk data. An attacker can craft malicious tickets containing embedded XSS payloads that execute when legitimate users view the helpdesk interface, enabling them to steal session cookies, modify user permissions, or access confidential support tickets containing personal data. The attack requires minimal privileges since only users with permission to change login-page images need to be compromised, making it particularly dangerous in environments where multiple administrators have access to this feature. Organizations using this helpdesk system face potential data breaches, unauthorized access to customer information, and possible lateral movement within their network infrastructure.
Mitigation strategies for this vulnerability should include immediate application of the vendor-provided security patches or updates that address the stored XSS flaw in the login page image handling functionality. System administrators should implement strict input validation and output encoding controls for all user-supplied content, particularly within administrative interfaces. Network segmentation and monitoring of helpdesk traffic can help detect anomalous behavior associated with crafted ticket submissions. Additionally, organizations should consider implementing web application firewalls to filter malicious payloads and regularly audit administrative privileges to limit access to login page customization features. The remediation approach should follow security best practices outlined in NIST SP 800-53 and OWASP Top Ten guidelines for preventing cross-site scripting vulnerabilities in web applications.