CVE-2018-10948 in Zimbra Collaboration Suite
Summary
by MITRE
Synacor Zimbra Admin UI in Zimbra Collaboration Suite before 8.8.0 beta 2 has Persistent XSS via mail addrs.
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Analysis
by VulDB Data Team • 09/25/2023
The vulnerability CVE-2018-10948 represents a persistent cross-site scripting flaw within the Synacor Zimbra Admin UI component of the Zimbra Collaboration Suite. This security weakness affects versions prior to 8.8.0 beta 2 and specifically targets the mail address handling functionality within the administrative interface. The vulnerability stems from inadequate input validation and output encoding mechanisms that fail to properly sanitize user-supplied data before it is rendered back to users within the web interface. Attackers can exploit this flaw by injecting malicious script code into mail address fields that are subsequently displayed to other administrators or users interacting with the Zimbra administration console.
The technical implementation of this vulnerability aligns with CWE-79 Cross-site Scripting attacks, where the flaw occurs in the context of a web application's user interface and involves the improper handling of untrusted data. The persistent nature of this XSS vulnerability means that malicious scripts injected by an attacker will remain active and execute each time the affected page is loaded or accessed by a victim. This particular vulnerability manifests when administrators or users view mail addresses that contain malicious payloads, allowing attackers to execute arbitrary JavaScript code within the context of the victim's browser session. The attack vector specifically targets the mail address input fields within the Zimbra Admin UI, making it particularly dangerous for privileged users who regularly interact with the administrative console.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to hijack administrator sessions, steal sensitive credentials, and potentially gain full control over the Zimbra Collaboration Suite environment. An attacker who successfully exploits this vulnerability can leverage the administrative privileges of the compromised user to modify system configurations, create new user accounts, access confidential email data, and establish persistent backdoors within the organization's email infrastructure. The persistent nature of the vulnerability means that even after the initial injection, the malicious scripts will continue to execute whenever affected pages are loaded, providing attackers with sustained access to the compromised environment. This makes the vulnerability particularly dangerous for organizations relying on Zimbra for email services, as it could lead to complete compromise of email infrastructure and potential data breaches.
Organizations affected by CVE-2018-10948 should immediately implement mitigations including updating to Zimbra Collaboration Suite version 8.8.0 beta 2 or later, which contains the necessary patches to address the XSS vulnerability. Additionally, administrators should implement input validation controls at the application level to sanitize all user-supplied data before it is processed or stored within the system. Network-level protections such as web application firewalls can provide additional defense-in-depth measures, though they should not be relied upon as the sole mitigation strategy. Security monitoring should be enhanced to detect unusual activity patterns that might indicate exploitation attempts, and regular security audits should be conducted to verify proper implementation of input sanitization and output encoding mechanisms. The vulnerability also highlights the importance of maintaining current security practices and implementing proper security testing procedures including automated scanning and manual penetration testing to identify similar weaknesses in web applications. According to ATT&CK framework, this vulnerability maps to T1059 Command and Scripting Interpreter and T1566 Phishing techniques, as attackers can use the XSS to deliver malicious payloads and establish initial access to the email infrastructure.