CVE-2014-8034 in WebEx Meetings Server
Summary
by MITRE
Cisco WebEx Meetings Server 1.5 presents the same CAPTCHA challenge for each login attempt, which makes it easier for remote attackers to obtain access via a brute-force approach of guessing usernames, aka Bug ID CSCuj40321.
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Analysis
by VulDB Data Team • 07/09/2017
The vulnerability identified as CVE-2014-8034 affects Cisco WebEx Meetings Server version 1.5, presenting a significant security weakness in the authentication mechanism that undermines the system's ability to resist automated attack vectors. This flaw manifests as a predictable authentication behavior where the same CAPTCHA challenge is presented to users during every login attempt, fundamentally weakening the server's defense against brute-force attacks. The vulnerability represents a critical failure in the authentication system design, as it removes the essential variable element that should make each authentication attempt unique and unpredictable to potential attackers. This predictable CAPTCHA implementation creates a direct pathway for malicious actors to systematically test username and password combinations without the normal friction that CAPTCHA mechanisms are designed to provide.
The technical implementation of this vulnerability stems from the server's failure to generate dynamic CAPTCHA challenges for each authentication attempt, which violates fundamental security principles for user authentication systems. According to CWE-307, this represents a weakness in authentication that allows for unauthorized access through excessive login attempts. The predictable nature of the CAPTCHA means that attackers can develop automated scripts that repeatedly submit login attempts while maintaining the same CAPTCHA solution, effectively bypassing the intended security controls. This vulnerability specifically impacts the authentication flow of the WebEx Meetings Server, where the system should enforce rate limiting and dynamic challenge-response mechanisms to prevent automated credential guessing attacks. The flaw operates at the application layer and directly affects the server's ability to distinguish between legitimate users and malicious actors attempting unauthorized access.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it creates an environment where attackers can systematically compromise multiple user accounts through automated brute-force campaigns. Attackers can leverage the predictable CAPTCHA mechanism to create highly efficient credential stuffing attacks, where they can rapidly cycle through common username and password combinations without being interrupted by dynamic CAPTCHA challenges. This vulnerability enables attackers to maintain persistent access attempts while circumventing traditional security measures, potentially leading to complete system compromise. The impact is particularly severe for organizations that rely on WebEx Meetings Server for business communications, as unauthorized access could result in data breaches, service disruption, and potential exfiltration of sensitive meeting content and participant information. The vulnerability also violates industry standards for secure authentication practices as outlined in NIST SP 800-63B, which emphasizes the importance of dynamic authentication challenges to prevent automated attacks.
Mitigation strategies for this vulnerability should focus on immediate implementation of dynamic CAPTCHA generation and enhanced authentication controls. Organizations should ensure that all authentication systems implement unique CAPTCHA challenges for each login attempt, as specified in the OWASP Authentication Cheat Sheet. The implementation of account lockout mechanisms and rate limiting should be enforced to prevent excessive login attempts from any single source. Additionally, multi-factor authentication should be enabled where possible to add additional layers of security beyond the basic username and password authentication. Regular security assessments should be conducted to identify similar authentication weaknesses, and system administrators should monitor login attempt patterns for signs of automated attack activity. The vulnerability also highlights the importance of proper security configuration management and regular patching of enterprise collaboration platforms to address known authentication weaknesses. Organizations should also consider implementing intrusion detection systems that can identify and alert on suspicious authentication patterns that may indicate brute-force attack attempts against their WebEx infrastructure.