CVE-2015-4276 in WebEx Meetings Server
Summary
by MITRE
Cisco WebEx Meetings Server 2.5MR1 allows remote authenticated users to execute arbitrary code via a crafted command parameter, aka Bug ID CSCus56138.
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Analysis
by VulDB Data Team • 06/03/2022
The vulnerability identified as CVE-2015-4276 represents a critical remote code execution flaw in Cisco WebEx Meetings Server version 2.5MR1. This vulnerability arises from insufficient input validation within the command parameter processing mechanism, creating an exploitable condition that allows authenticated attackers to inject and execute arbitrary commands on the affected system. The flaw specifically impacts the server's handling of user-supplied parameters, where proper sanitization and validation procedures are absent or inadequate. This type of vulnerability falls under the category of command injection attacks, which are classified as CWE-77 in the Common Weakness Enumeration catalog, representing a fundamental security weakness in software development practices.
The operational impact of this vulnerability extends beyond simple privilege escalation, as authenticated users can leverage this flaw to gain complete control over the WebEx Meetings Server. Attackers can execute malicious commands with the privileges of the WebEx service account, potentially leading to full system compromise, data exfiltration, and persistence mechanisms. The vulnerability affects organizations that rely on WebEx for video conferencing and collaboration, making it particularly dangerous in enterprise environments where meeting servers handle sensitive business communications and proprietary information. The attack vector requires only authenticated access, which means that even users with limited privileges could potentially exploit this weakness if they can authenticate to the system. This aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, as attackers can execute arbitrary commands through the vulnerable parameter handling.
The exploitation of CVE-2015-4276 demonstrates a critical flaw in the server's security architecture where input validation mechanisms fail to properly sanitize user-supplied data before processing. The vulnerability essentially allows attackers to bypass authentication controls by crafting malicious command parameters that are then executed by the server without proper verification. This weakness enables attackers to perform operations such as file system manipulation, process execution, and network communication from within the server environment. Organizations using this version of WebEx Meetings Server face significant risk of data breaches and system compromise, as the vulnerability can be leveraged to establish persistent access to their collaboration infrastructure. The flaw particularly affects environments where WebEx servers are deployed in untrusted network segments, as the authenticated nature of the attack does not require network-level access to exploit.
Mitigation strategies for CVE-2015-4276 should include immediate patching of the WebEx Meetings Server to the latest available version that addresses this vulnerability. Cisco released security updates specifically designed to resolve this issue, and organizations must ensure they deploy these patches promptly to eliminate the risk. Network segmentation and access controls should be implemented to limit the number of authenticated users who can interact with the WebEx server, reducing the attack surface. Additionally, monitoring and logging of server activities should be enhanced to detect suspicious command execution patterns that may indicate exploitation attempts. Organizations should also consider implementing web application firewalls and input validation controls to provide additional layers of protection against similar vulnerabilities in other applications. The remediation process must include thorough testing of patches to ensure they do not introduce compatibility issues with existing WebEx functionality, while also validating that the security controls are properly configured and functioning as intended.