CVE-2018-10950 in Zimbra Collaboration
Summary
by MITRE
mailboxd in Zimbra Collaboration Suite 8.8 before 8.8.8; 8.7 before 8.7.11.Patch3; and 8.6 before 8.6.0.Patch10 allows Information Exposure through Verbose Error Messages containing a stack dump, tracing data, or full user-context dump.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 06/05/2020
The vulnerability identified as CVE-2018-10950 affects the mailboxd service within Zimbra Collaboration Suite across multiple versions including 8.8 before 8.8.8, 8.7 before 8.7.11.Patch3, and 8.6 before 8.6.0.Patch10. This represents a critical information exposure flaw that occurs when the system generates verbose error messages containing sensitive technical data. The vulnerability stems from inadequate error handling mechanisms within the mailboxd component, which fails to sanitize error outputs before presenting them to users or system logs. When certain operations fail or encounter exceptions, the system dumps complete stack traces, debugging information, and user context data directly into error responses, creating a significant security risk.
The technical implementation of this vulnerability manifests through improper exception handling within the Zimbra mailboxd service. When processing requests that trigger internal failures, the system does not filter or obfuscate sensitive data from error messages, resulting in exposure of system internals including file paths, database connection details, user session information, and potentially authentication tokens. This behavior directly aligns with CWE-209, which defines "Information Exposure Through an Error Message" as a weakness where error messages contain sensitive information that could aid attackers in understanding system architecture and identifying potential attack vectors. The flaw represents a classic case of insufficient logging and error reporting controls that violate fundamental security principles of least privilege and defense in depth.
The operational impact of this vulnerability extends beyond simple information disclosure, as the exposed data can significantly aid attackers in conducting more sophisticated attacks against the Zimbra environment. The stack traces and system context information provide attackers with detailed knowledge of the application's internal structure, potentially revealing database schemas, API endpoints, and system configurations. This information can be leveraged to craft targeted attacks such as SQL injection attempts, cross-site scripting exploits, or privilege escalation maneuvers. According to ATT&CK framework reference T1212, adversaries can use information from exposed error messages to gather intelligence about the target system, which directly correlates with the threat posed by this vulnerability. The exposure of user context data particularly increases risk for credential harvesting and session hijacking attacks, as attackers could potentially reconstruct user sessions or identify valid authentication patterns.
Organizations utilizing affected Zimbra versions should immediately implement comprehensive mitigation strategies to address this vulnerability. The primary remediation involves upgrading to patched versions of Zimbra Collaboration Suite, specifically versions 8.8.8, 8.7.11.Patch3, and 8.6.0.Patch10 where the error handling has been properly enhanced. Additionally, system administrators should implement centralized logging with proper log sanitization mechanisms that prevent sensitive data from appearing in error messages. Network monitoring solutions should be configured to detect and alert on unusual error message patterns that might indicate exploitation attempts. Security controls should include implementing proper error handling frameworks that generate generic, non-descriptive error messages for end users while preserving detailed technical information in secure audit logs. The vulnerability demonstrates the critical importance of secure coding practices and proper error management in enterprise collaboration platforms, where the exposure of internal system information can create cascading security risks throughout the entire infrastructure.