CVE-2018-14013 in Zimbra Collaboration Suite
Summary
by MITRE
Synacor Zimbra Collaboration Suite Collaboration before 8.8.11 has XSS in the AJAX and html web clients.
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Analysis
by VulDB Data Team • 09/24/2023
The Synacor Zimbra Collaboration Suite represents a widely deployed enterprise email and collaboration platform that serves organizations globally for their communication needs. This particular vulnerability CVE-2018-14013 affects versions prior to 8.8.11 and specifically targets the AJAX and HTML web clients of the platform. The vulnerability manifests as a cross-site scripting flaw that allows attackers to inject malicious scripts into web pages viewed by other users. This type of vulnerability falls under the Common Weakness Enumeration category CWE-79 which specifically addresses Cross-Site Scripting vulnerabilities in web applications. The affected clients represent the primary interface through which users interact with the collaboration suite, making this a critical security concern for enterprise environments where sensitive data is routinely handled.
The technical implementation of this XSS vulnerability stems from insufficient input validation and output encoding within the AJAX and HTML web client components of Zimbra. When users access certain web pages or interact with specific features within the collaboration suite, the application fails to properly sanitize user-supplied data before rendering it in the browser context. Attackers can exploit this weakness by crafting malicious payloads that, when executed, can perform actions on behalf of authenticated users. The vulnerability is particularly concerning because it affects the web client interfaces which are frequently used by employees and administrators, potentially allowing threat actors to escalate privileges, steal session cookies, or redirect users to malicious sites. This weakness enables attackers to leverage the trust relationship between the user and the application, making the attack vector particularly effective in enterprise environments.
The operational impact of this vulnerability extends beyond simple script execution, as it can lead to complete compromise of user sessions and potential data breaches within enterprise environments. An attacker who successfully exploits this vulnerability could access sensitive emails, calendar entries, contacts, and other collaboration data that users have stored in their Zimbra accounts. The attack surface is significantly broadened because the web clients are used by employees across various departments, potentially providing access to financial records, intellectual property, and other confidential information. This vulnerability also aligns with ATT&CK technique T1531 which describes the use of web shell and client-side attacks to maintain persistence and escalate privileges within compromised environments. The impact is particularly severe in organizations where Zimbra serves as the primary collaboration platform, as it represents a single point of failure that could compromise multiple users simultaneously.
Organizations affected by this vulnerability should immediately implement mitigation strategies including applying the available security patches from Synacor, which address the input validation and output encoding deficiencies in the affected web clients. Network segmentation and monitoring should be enhanced to detect suspicious traffic patterns that may indicate exploitation attempts. Additional protective measures include implementing content security policies that restrict script execution within the web application context, and conducting thorough security awareness training for users to recognize potential phishing attempts that may leverage this vulnerability. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches in enterprise collaboration platforms, as unpatched systems represent significant attack vectors for threat actors. Organizations should also consider implementing web application firewalls to provide additional layers of protection against XSS attacks and other web-based threats that target collaboration platforms. This vulnerability serves as a reminder of the necessity for continuous security monitoring and rapid patch deployment in enterprise environments where collaboration platforms serve as critical infrastructure components.