CVE-2019-14351 in EspoCRM
Summary
by MITRE
EspoCRM 5.6.4 is vulnerable to user password hash enumeration. A malicious authenticated attacker can brute-force a user password hash by 1 symbol at a time using specially crafted api/v1/User?filterList filters.
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Analysis
by VulDB Data Team • 11/13/2023
The vulnerability identified as CVE-2019-14351 affects EspoCRM version 5.6.4 and represents a critical security flaw in the authentication system that enables password hash enumeration. This vulnerability allows authenticated attackers to systematically determine user password hashes by employing a time-based brute force approach through the api/v1/User endpoint with specific filterList parameters. The flaw stems from the application's insufficient validation and response handling during user authentication attempts, creating a predictable pattern that reveals information about the password hash structure.
The technical implementation of this vulnerability exploits the application's API response behavior when processing user filter queries. When an attacker submits crafted filterList parameters to the api/v1/User endpoint, the system responds with different timing characteristics or error messages that correlate with the correctness of partial password hash guesses. This timing differential creates a side-channel attack vector that enables attackers to enumerate password hashes one character at a time, significantly reducing the computational complexity of password cracking efforts. The vulnerability is classified under CWE-208 as "Information Exposure Through Timing Discrepancy" and aligns with ATT&CK technique T1212 as "Exploitation for Credential Access" through timing-based information leakage.
The operational impact of this vulnerability is severe as it directly undermines the security of user accounts within the EspoCRM system. An authenticated attacker with access to the application can systematically compromise multiple user accounts by enumerating their password hashes, which can then be subjected to offline brute force attacks or rainbow table lookups. This vulnerability affects the confidentiality and integrity of the authentication system, potentially leading to unauthorized access to sensitive customer data, business communications, and administrative functions within the CRM environment. The exposure of password hash structures also enables attackers to craft more sophisticated attacks against other systems that may share similar credentials.
Mitigation strategies for CVE-2019-14351 should focus on implementing constant-time comparison algorithms for password validation and ensuring consistent API response timing regardless of input values. Organizations should immediately apply the vendor-provided security patches and updates to address the specific implementation flaw in the user authentication API endpoint. Additional protective measures include implementing rate limiting and account lockout mechanisms for API access attempts, as well as monitoring for unusual patterns of API usage that may indicate enumeration attacks. The system should be configured to return identical error responses for all authentication attempts, regardless of whether the username exists or the password is correct, thereby eliminating the timing side-channel that enables this vulnerability. Security teams should also conduct comprehensive testing to ensure that all API endpoints properly handle authentication requests without exposing information about the underlying password structures through timing variations or differential responses.