CVE-2017-12295 in WebEx Meetings Server
Summary
by MITRE
A vulnerability in Cisco WebEx Meetings Server could allow an unauthenticated, remote attacker to access sensitive data about the application. An attacker could exploit this vulnerability to gain information to conduct additional reconnaissance attacks. The vulnerability is due to the HTTP header reply from the Cisco WebEx Meetings Server to the client, which could include internal network information that should be restricted. An attacker could exploit the vulnerability by attempting to use the HTTP protocol and looking at the data in the HTTP responses from the Cisco WebEx Meetings Server. An exploit could allow the attacker to discover sensitive data about the application. Cisco Bug IDs: CSCve65818.
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Analysis
by VulDB Data Team • 01/21/2021
The vulnerability identified as CVE-2017-12295 represents a critical information disclosure flaw within Cisco WebEx Meetings Server that exposes internal network details through improperly configured HTTP responses. This weakness falls under the broader category of information exposure vulnerabilities that can significantly compromise the security posture of enterprise communication platforms. The vulnerability stems from the server's failure to properly sanitize HTTP headers in its responses, allowing sensitive internal network information to leak to unauthorized external parties. The flaw specifically affects the server's HTTP protocol implementation where it inadvertently includes internal system details in response headers that should remain restricted to authorized internal processes. This type of vulnerability directly aligns with CWE-200, which categorizes information exposure issues as a fundamental security concern where systems unintentionally reveal sensitive information to unauthorized actors.
The technical exploitation of this vulnerability requires minimal prerequisites as attackers need only send HTTP requests to the affected Cisco WebEx Meetings Server without authentication. The attack vector leverages the server's response handling mechanism where HTTP headers contain internal network topology information, server identifiers, or other sensitive metadata that should remain confidential. When an attacker crafts specific HTTP requests and analyzes the responses, they can extract valuable reconnaissance data about the internal network infrastructure, server configurations, and potentially other connected systems. This information leakage creates a foundation for more sophisticated attacks as adversaries can use the discovered data to plan targeted exploitation attempts against other vulnerable components within the network. The vulnerability demonstrates a classic case of insufficient output filtering where the server fails to properly validate and sanitize its response headers before transmitting them to clients.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables attackers to conduct comprehensive reconnaissance activities that can lead to more serious security incidents. The leaked information could include server version details, internal IP addresses, network topology information, and potentially other system identifiers that would normally be restricted to authorized administrators. This reconnaissance capability allows threat actors to map the internal network structure and identify potential attack vectors that could be used to compromise additional systems within the organization. The vulnerability's remote nature means that attackers can exploit it from anywhere on the internet without requiring physical access or valid credentials, making it particularly dangerous for organizations that rely on WebEx for business communications. The exposure of internal network information creates a significant risk for organizations that may have other systems with similar vulnerabilities or weak security controls.
Organizations affected by this vulnerability should implement immediate mitigations including updating to patched versions of Cisco WebEx Meetings Server, configuring proper HTTP header filtering, and implementing network segmentation to limit access to the affected systems. The remediation process should involve reviewing and hardening the server's HTTP response handling to ensure that sensitive information is not included in headers sent to external clients. Network administrators should also implement monitoring solutions to detect unusual HTTP request patterns that might indicate exploitation attempts. Additionally, organizations should conduct comprehensive security assessments to identify other systems that might be vulnerable to similar information disclosure issues, particularly those that improperly handle HTTP responses or lack proper output sanitization controls. The vulnerability highlights the critical importance of proper input and output validation in web applications and serves as a reminder of the potential consequences when security controls fail to properly filter sensitive information from system responses.