CVE-2021-42089 in Zammad
Summary
by MITRE • 10/08/2021
An issue was discovered in Zammad before 4.1.1. The REST API discloses sensitive information.
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Analysis
by VulDB Data Team • 10/14/2021
The vulnerability identified as CVE-2021-42089 represents a critical information disclosure flaw within the Zammad collaboration platform, specifically affecting versions prior to 4.1.1. This issue manifests through the REST API component which inadvertently exposes sensitive data to unauthorized users. Zammad is a comprehensive customer service platform that includes ticketing systems, chat functionality, and various communication tools that organizations rely upon for managing client interactions. The vulnerability arises from insufficient access controls and data filtering mechanisms within the API endpoints, allowing malicious actors to retrieve information that should remain restricted to authorized personnel only.
The technical nature of this flaw stems from improper input validation and authorization checks within the REST API framework. When legitimate API requests are processed, the system fails to adequately verify user permissions before returning response data, potentially exposing user credentials, personal information, system configurations, or other confidential details. This type of vulnerability aligns with CWE-200, which categorizes improper output sanitization and information exposure issues. The flaw operates at the application layer where API requests are handled, making it particularly dangerous as it can be exploited through network-based attacks without requiring physical access to the system infrastructure.
The operational impact of this vulnerability extends beyond simple data leakage, creating significant risks for organizations using Zammad platforms. Attackers who exploit this flaw can gain access to sensitive user data including personal identification information, communication records, and potentially system administrative credentials. This exposure can lead to identity theft, unauthorized access to customer accounts, and potential escalation of privileges within the platform. Organizations relying on Zammad for customer service operations face increased risk of data breaches and compliance violations, particularly in regulated industries where customer data protection is mandatory. The vulnerability also creates opportunities for further attacks, as stolen information can be used to conduct social engineering campaigns or launch targeted attacks against other systems within the organization.
Organizations should immediately implement mitigations including updating to Zammad version 4.1.1 or later, which contains the necessary patches to address the information disclosure issue. Network segmentation and API rate limiting can provide additional protective layers while the primary update is being deployed. Security monitoring should be enhanced to detect unusual API access patterns that might indicate exploitation attempts. Access controls should be reviewed and strengthened to ensure proper authentication and authorization mechanisms are in place. The ATT&CK framework categorizes this type of vulnerability under T1071.004 for application layer protocol usage, and T1566 for credential access through API exploitation techniques. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other components of the system architecture. Organizations should also consider implementing automated patch management processes to ensure timely deployment of security updates across all platform components.