CVE-2019-8947 in Zimbra Collaboration
Summary
by MITRE
Zimbra Collaboration 8.7.x - 8.8.11P2 contains non-persistent XSS.
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Analysis
by VulDB Data Team • 03/27/2024
The vulnerability identified as CVE-2019-8947 affects Zimbra Collaboration software versions 8.7.x through 8.8.11P2, representing a cross-site scripting flaw that allows attackers to inject malicious scripts into web applications. This issue specifically manifests as a non-persistent cross-site scripting vulnerability, meaning the malicious code does not get stored on the server but is instead executed in the victim's browser when they interact with the compromised application interface. The vulnerability stems from insufficient input validation and output encoding within the Zimbra web client, creating an attack surface where user-supplied data can be manipulated to execute arbitrary JavaScript code in the context of the victim's browser session.
The technical implementation of this vulnerability occurs when the application fails to properly sanitize user inputs before rendering them in web pages, particularly in areas where email content, subject lines, or other user-generated fields are displayed. Attackers can craft malicious payloads that exploit this weakness by embedding script tags or other malicious code within email headers, message bodies, or other input fields that are subsequently rendered by the web interface. The non-persistent nature means that the malicious scripts are executed only during the current browsing session and do not persist in the application's database or storage systems, making the attack more difficult to detect and maintain but still highly dangerous for active users.
The operational impact of CVE-2019-8947 extends beyond simple script execution, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, data exfiltration, and privilege escalation within the Zimbra environment. An attacker who successfully exploits this vulnerability could potentially access sensitive email communications, impersonate legitimate users, or use the compromised session to perform unauthorized actions within the collaboration platform. The attack vector typically involves social engineering to trick users into clicking on malicious links or opening compromised emails that contain the XSS payload, making this vulnerability particularly dangerous in enterprise environments where users frequently interact with email systems.
Organizations utilizing affected Zimbra versions should prioritize immediate remediation through official patches provided by Zimbra, as the vulnerability represents a significant security risk that can lead to complete compromise of email systems and associated user data. The mitigation strategy should include comprehensive application patching, implementation of web application firewalls to detect and block malicious payloads, and enhanced user education regarding phishing and social engineering attacks. Security teams should also conduct thorough vulnerability assessments to identify any additional attack vectors within the email infrastructure and consider implementing Content Security Policy headers to limit the execution of unauthorized scripts. This vulnerability aligns with CWE-79, which categorizes cross-site scripting flaws as one of the most prevalent web application security vulnerabilities, and maps to ATT&CK technique T1059.007 for scripting languages and T1566 for phishing attacks that leverage XSS as an initial access vector.