CVE-2018-0356 in WebEx
Summary
by MITRE
A vulnerability in the web framework of Cisco WebEx could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against the user of the web interface of an affected system. The vulnerability is due to insufficient input validation of certain parameters that are passed to the affected software via the HTTP GET and HTTP POST methods. An attacker who can convince a user to follow an attacker-supplied link could execute arbitrary script or HTML code in the user's browser in the context of an affected site. Cisco Bug IDs: CSCvi63757.
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Analysis
by VulDB Data Team • 03/22/2023
The vulnerability identified as CVE-2018-0356 represents a critical cross-site scripting flaw within Cisco WebEx's web framework that exposes users to remote code execution risks. This vulnerability specifically targets the insufficient input validation mechanisms implemented in the web interface, creating an exploitable condition that allows malicious actors to inject arbitrary scripts into user browsers. The flaw manifests when the affected software processes HTTP GET and HTTP POST parameters without adequate sanitization, creating a pathway for attackers to manipulate the application's behavior through crafted input vectors. The vulnerability's classification aligns with CWE-79, which defines cross-site scripting as a common web application security weakness where untrusted data is incorporated into web pages without proper validation or encoding.
The operational impact of this vulnerability extends beyond simple script injection, as it enables attackers to execute malicious code within the context of a victim's browser session. An unauthenticated attacker can craft malicious links that, when clicked by a user, will execute arbitrary HTML or JavaScript code in the victim's browser, potentially leading to session hijacking, data theft, or further exploitation of the compromised user's privileges. The attack vector relies on social engineering techniques where users are convinced to follow attacker-controlled links, making this vulnerability particularly dangerous in enterprise environments where users frequently interact with web-based collaboration tools. This weakness directly violates the principle of least privilege and demonstrates a failure in the principle of input validation that is fundamental to secure web application development.
The security implications of CVE-2018-0356 are significant given the widespread use of Cisco WebEx in enterprise and organizational settings where collaboration and communication tools are frequently accessed by employees with varying levels of security awareness. The vulnerability's exploitation requires minimal technical skill from attackers, as it leverages the inherent trust users place in legitimate web applications. This makes the attack surface particularly broad and increases the likelihood of successful exploitation across diverse user populations. Organizations utilizing WebEx services face potential data breaches, unauthorized access to sensitive information, and possible compromise of entire network infrastructures if users fall victim to these attacks. The vulnerability's persistence in the web interface means that all users interacting with the affected WebEx platform are at risk, regardless of their security training or technical expertise levels.
Mitigation strategies for CVE-2018-0356 should prioritize immediate patching of affected systems and implementation of comprehensive input validation measures. Organizations must ensure that all HTTP GET and POST parameters are properly sanitized and validated before being processed by the web application. The recommended approach includes implementing proper output encoding, utilizing Content Security Policy headers, and deploying web application firewalls to detect and prevent malicious input patterns. Security teams should also consider implementing user education programs to raise awareness about phishing attempts and suspicious links that may exploit this vulnerability. Additionally, network monitoring should be enhanced to detect unusual traffic patterns that might indicate exploitation attempts. The vulnerability's remediation aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation would enable attackers to execute malicious scripts within the user's browser context. Organizations should also review their incident response procedures to ensure rapid detection and containment of any potential exploitation attempts, given the vulnerability's ability to enable persistent access through session hijacking and credential theft mechanisms.