CVE-2017-6762 in Guest Server
Summary
by MITRE
A vulnerability in the web-based management interface of Cisco Jabber Guest Server 10.6(9), 11.0(0), and 11.0(1) could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the web-based management interface of the affected software. The vulnerability is due to insufficient validation of user-supplied input by the web-based management interface of the affected software. An attacker could exploit this vulnerability by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the interface or allow the attacker to access sensitive browser-based information. Cisco Bug IDs: CSCve09718.
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Analysis
by VulDB Data Team • 01/07/2021
The vulnerability described in CVE-2017-6762 represents a critical cross-site scripting flaw within Cisco Jabber Guest Server's web-based management interface. This security weakness affects versions 10.6(9), 11.0(0), and 11.0(1) of the software, creating a significant attack surface for remote threat actors. The vulnerability stems from inadequate input validation mechanisms within the web interface, specifically failing to properly sanitize user-supplied data before processing or rendering it back to users. This fundamental flaw in the application's security architecture allows malicious actors to inject malicious scripts into the web interface, potentially compromising the security of legitimate users who interact with the system.
The exploitation of this vulnerability requires an attacker to craft a malicious link and persuade a victim user to click it, leveraging social engineering techniques to achieve initial access. This approach aligns with common attack patterns documented in the ATT&CK framework under the T1566 technique category, which focuses on social engineering methods for initial access. Once successfully exploited, the XSS attack could enable the attacker to execute arbitrary script code within the context of the web interface, potentially gaining unauthorized access to sensitive browser-based information. The vulnerability's impact extends beyond simple script execution, as it could provide attackers with the capability to hijack user sessions, steal authentication tokens, or access confidential data that the legitimate user has access to within the application environment.
From a technical perspective, this vulnerability manifests as a classic reflected XSS attack vector where user input is not properly escaped or validated before being rendered in the web interface. The affected Cisco Jabber Guest Server components handle user-supplied data through parameters or input fields that are subsequently processed without adequate sanitization measures. This creates an environment where malicious payloads can be injected and executed when the vulnerable interface renders the malformed input. The security implications are particularly concerning given that the web-based management interface typically requires elevated privileges for access, making successful exploitation potentially devastating for network security. The vulnerability's classification under CWE-79, which specifically addresses cross-site scripting flaws, underscores the fundamental nature of the input validation failure.
Organizations utilizing affected Cisco Jabber Guest Server versions face significant operational risks due to this vulnerability. The unauthenticated nature of the attack means that threat actors do not require valid credentials to initiate exploitation attempts, making the system particularly vulnerable to automated scanning and attack campaigns. The potential for session hijacking and data exfiltration creates a substantial threat to enterprise security infrastructure, particularly in environments where the Jabber Guest Server manages guest access and user authentication. Network administrators must consider the broader implications of this vulnerability within their security posture, as it could serve as a foothold for more sophisticated attacks or provide attackers with additional reconnaissance capabilities. The vulnerability's presence in multiple software versions indicates a systemic issue within the application's development lifecycle, highlighting potential gaps in security testing and code review processes.
Effective mitigation strategies for this vulnerability should include immediate implementation of Cisco's security patches and updates, which address the underlying input validation deficiencies. Network segmentation and access controls should be strengthened to limit exposure of the affected web interface to trusted users only. Additionally, implementing web application firewalls and content security policies can provide additional layers of protection against XSS attacks. Security monitoring should be enhanced to detect anomalous user behavior patterns that might indicate exploitation attempts. Organizations should also conduct comprehensive security assessments of their Cisco Jabber Guest Server deployments to identify any additional vulnerabilities that may exist within the broader application ecosystem. The remediation process should follow established security frameworks and include thorough testing to ensure that updates do not introduce regressions or compatibility issues within the existing infrastructure.