CVE-2017-5619 in Zammad
Summary
by MITRE
An issue was discovered in Zammad before 1.0.4, 1.1.x before 1.1.3, and 1.2.x before 1.2.1. Attackers can login with the hashed password itself (e.g., from the DB) instead of the valid password string.
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Analysis
by VulDB Data Team • 09/06/2020
The vulnerability identified as CVE-2017-5619 represents a critical authentication flaw in the Zammad help desk software ecosystem affecting multiple version streams including 1.0.3 and earlier, 1.1.2 and earlier, and 1.2.0 and earlier releases. This vulnerability stems from a fundamental misconfiguration in the password validation mechanism that allows attackers to bypass legitimate authentication processes by submitting hashed password values directly instead of proper plaintext credentials. The flaw exists at the core authentication layer where the system fails to properly differentiate between valid password strings and their corresponding hash representations during the login verification process.
This vulnerability directly maps to CWE-287 which addresses improper authentication issues in software systems. The technical implementation error occurs when the authentication subsystem accepts a pre-hashed password value as if it were a legitimate user password, effectively creating a backdoor authentication mechanism. The flaw essentially allows an attacker to authenticate as any user by simply providing the password hash from the database, eliminating the need to guess or crack the actual password. This represents a severe deviation from standard authentication practices where password hashes should only be used for verification purposes and never accepted as valid input for login operations.
The operational impact of this vulnerability is substantial as it provides attackers with immediate unauthorized access to user accounts without requiring knowledge of actual passwords or any password recovery mechanisms. An attacker can leverage this vulnerability to gain full access to user sessions, view sensitive customer data, modify support tickets, and potentially escalate privileges within the system. The vulnerability is particularly dangerous because it affects the entire user base and can be exploited by anyone who can access the database or obtain password hash values through other means such as SQL injection attacks or data breaches. This flaw undermines the fundamental security principle of least privilege and creates a persistent threat vector that remains active until the software is properly patched.
The recommended mitigations for CVE-2017-5619 involve immediate deployment of patched versions of Zammad software as specified in the advisory releases 1.0.4, 1.1.3, and 1.2.1. Organizations should also implement comprehensive monitoring to detect any unauthorized access attempts and conduct thorough security assessments of their authentication mechanisms. System administrators should ensure that password hashes are never exposed in user-facing interfaces and that proper input validation is implemented to reject hash values during authentication processes. The vulnerability aligns with ATT&CK technique T1110.003 which covers credential access through password reuse and weak authentication mechanisms, making it particularly relevant for security teams implementing defensive strategies against credential-based attacks. Additionally, organizations should review their database access controls and implement proper segregation of duties to prevent unauthorized access to password hash storage areas.