CVE-2015-4194 in WebEx Meeting Center
Summary
by MITRE
The web-based administrative interface in Cisco WebEx Meeting Center provides different error messages for failed login attempts depending on whether the username exists or corresponds to a privileged account, which allows remote attackers to enumerate account names and obtain sensitive information via a series of requests, aka Bug ID CSCuf28861.
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Analysis
by VulDB Data Team • 05/21/2022
This vulnerability exists in the web-based administrative interface of Cisco WebEx Meeting Center where the system provides different error messages for failed login attempts based on whether the username exists in the system or corresponds to a privileged account. The flaw stems from an insecure error handling mechanism that inadvertently reveals information about account existence and privilege levels to unauthorized users. Attackers can exploit this behavior by sending multiple login requests with different usernames to determine which accounts exist within the system and identify potentially privileged user accounts. This type of information disclosure vulnerability is classified under CWE-209, which specifically addresses the issue of error messages containing sensitive information. The vulnerability enables account enumeration attacks that can lead to more sophisticated exploitation attempts.
The technical implementation of this flaw occurs at the authentication layer of the web interface where the system's response logic differentiates between invalid usernames and invalid passwords for existing accounts. When an attacker attempts to log in with a non-existent username, the system returns one type of error message, but when attempting to log in with an existing username but incorrect password, it returns a different message indicating the account exists but the credentials are wrong. This differential response pattern allows attackers to systematically test usernames and distinguish between valid and invalid account names. The vulnerability operates at the application level and represents a classic example of how error handling can introduce security weaknesses that provide attackers with valuable reconnaissance information.
The operational impact of this vulnerability extends beyond simple account enumeration to potentially enable more serious attacks including credential stuffing, brute force attempts against identified accounts, and privilege escalation attacks. Once an attacker has identified valid usernames and potentially privileged accounts, they can focus their efforts on these targets, significantly increasing the success rate of subsequent attacks. The vulnerability affects the confidentiality and integrity aspects of the system's security model by allowing unauthorized information disclosure. According to ATT&CK framework, this vulnerability maps to T1087.001 - Account Discovery and T1110.001 - Brute Force, as it enables both reconnaissance and credential-based attacks. The exposure of account information can lead to further compromise of the system through targeted attacks against identified privileged accounts.
Mitigation strategies for this vulnerability should focus on implementing consistent error handling across authentication mechanisms to ensure that all failed login attempts return identical error messages regardless of whether the username exists or the account has privileged status. Organizations should configure the WebEx Meeting Center interface to use generic error messages that do not disclose account existence information. Additionally, implementing account lockout mechanisms, rate limiting, and multi-factor authentication can help reduce the effectiveness of enumeration attacks. The system should also be configured with proper logging and monitoring to detect suspicious login patterns and potential enumeration attempts. Security patches from Cisco should be applied immediately to address this vulnerability, and network segmentation should be implemented to limit access to the administrative interface to authorized personnel only. Regular security assessments should be conducted to identify similar information disclosure issues in other applications and systems within the organization's infrastructure.