CVE-2020-3136 in Jabber Guest
Summary
by MITRE
[CVE-2020-3136_su] A vulnerability in the web-based management interface of Cisco Jabber Guest could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the web-based management interface of an affected device. The vulnerability exists because the web-based management interface of the affected device does not properly validate user-supplied input. An attacker could exploit this vulnerability by persuading a user to click a malicious link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or to access sensitive, browser-based information.
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Analysis
by VulDB Data Team • 03/26/2024
The vulnerability identified as CVE-2020-3136 resides within the web-based management interface of Cisco Jabber Guest, representing a critical security flaw that enables unauthenticated remote attackers to execute cross-site scripting attacks. This vulnerability stems from inadequate input validation mechanisms within the affected web interface, creating an exploitable entry point that undermines the security posture of Cisco Jabber Guest deployments. The flaw specifically affects the validation of user-supplied input, which fails to properly sanitize or filter malicious content before processing, allowing attackers to inject harmful scripts into the application's response.
The technical exploitation of this vulnerability occurs through social engineering tactics where attackers craft malicious links designed to target unsuspecting users of the web-based management interface. When victims click these crafted links, the malicious scripts execute within the context of their browser session, effectively bypassing traditional security boundaries. This cross-site scripting vulnerability operates under the CWE-79 classification, which specifically addresses cross-site scripting flaws that enable attackers to inject client-side scripts into web applications. The attack vector leverages the trust relationship between the user and the web interface, making it particularly dangerous as users may not recognize the malicious nature of the links they interact with.
The operational impact of this vulnerability extends beyond simple script execution, as successful exploitation could provide attackers with the ability to access sensitive browser-based information and execute arbitrary code within the web interface context. This capability allows adversaries to potentially escalate their privileges, access confidential data, or manipulate the web-based management interface to perform unauthorized actions. The vulnerability's remote and unauthenticated nature means that attackers do not require prior credentials or physical access to the affected system, significantly expanding the attack surface and reducing the barriers to exploitation. According to ATT&CK framework, this vulnerability maps to T1059.007 for script execution and T1566 for social engineering techniques, highlighting both the execution and initial access components of the attack chain.
Organizations utilizing Cisco Jabber Guest must implement immediate mitigations to address this vulnerability, including applying the latest security patches from Cisco and implementing web application firewalls to filter malicious input. Network segmentation and user education programs can help reduce the risk of successful exploitation through social engineering. The vulnerability demonstrates the critical importance of input validation in web applications, particularly in management interfaces where administrative functions are accessible. Security teams should conduct thorough assessments of their Cisco Jabber Guest deployments to identify and remediate similar validation weaknesses that may exist in other web-based management interfaces. Regular security testing and vulnerability assessments remain essential to identifying and addressing potential XSS vulnerabilities before they can be exploited by malicious actors.