CVE-2017-6081 in Zammad
Summary
by MITRE
A CSRF issue was discovered in Zammad before 1.0.4, 1.1.x before 1.1.3, and 1.2.x before 1.2.1. To exploit the vulnerability, an attacker can send cross-domain requests directly to the REST API for users with a valid session cookie.
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Analysis
by VulDB Data Team • 09/06/2020
The vulnerability identified as CVE-2017-6081 represents a critical cross-site request forgery flaw in the Zammad helpdesk system that affected multiple version branches including 1.0.3 and earlier, 1.1.2 and earlier, and 1.2.0 and earlier releases. This weakness stems from the absence of proper anti-CSRF protection mechanisms within the application's REST API endpoints, creating a significant security risk for organizations relying on the platform for customer support and internal communication management.
The technical implementation of this vulnerability allows attackers to exploit the lack of CSRF token validation in Zammad's API interfaces. When legitimate users maintain active sessions with valid session cookies, malicious actors can craft malicious web pages or send crafted cross-domain requests that automatically leverage these authenticated sessions. The flaw specifically affects the REST API components that handle user management and administrative functions, enabling unauthorized modifications to user accounts, password resets, and potentially full system compromise depending on the user's privileges. This vulnerability operates at the application layer and directly violates the principle of least privilege by allowing unauthorized actions through authenticated sessions without proper validation of the request origin.
The operational impact of CVE-2017-6081 extends beyond simple data theft or modification, as it can enable complete account takeover scenarios and privilege escalation attacks. An attacker with knowledge of a victim's active session cookie can perform actions such as creating new user accounts, modifying existing user permissions, resetting passwords, and accessing sensitive information through the API endpoints. The vulnerability's cross-domain nature means that attacks can be executed from any domain, making detection and prevention particularly challenging. Organizations using affected Zammad versions face significant risk of unauthorized access to their support ticket systems, customer data exposure, and potential disruption of business operations. This vulnerability aligns with CWE-352, which specifically addresses Cross-Site Request Forgery, and maps to ATT&CK technique T1566.002 for credential access through social engineering and T1078 for valid accounts exploitation.
The recommended mitigation strategy involves immediate patching of affected Zammad installations to versions 1.0.4, 1.1.3, or 1.2.1, which contain proper CSRF protection mechanisms. Organizations should also implement additional security controls including the enforcement of SameSite cookies, implementation of proper anti-CSRF tokens for API endpoints, and regular monitoring of authentication logs for suspicious activities. Network-level protections such as web application firewalls can provide additional defense-in-depth, while security teams should conduct comprehensive vulnerability assessments to identify any other potentially affected components within their Zammad deployments. The vulnerability highlights the critical importance of implementing proper session management and request validation mechanisms in web applications, particularly those handling sensitive user data and administrative functions.