CVE-2018-0112 in WebEx Business Suite Client
Summary
by MITRE
A vulnerability in Cisco WebEx Business Suite clients, Cisco WebEx Meetings, and Cisco WebEx Meetings Server could allow an authenticated, remote attacker to execute arbitrary code on a targeted system. The vulnerability is due to insufficient input validation by the Cisco WebEx clients. An attacker could exploit this vulnerability by providing meeting attendees with a malicious Flash (.swf) file via the file-sharing capabilities of the client. Exploitation of this vulnerability could allow arbitrary code execution on the system of a targeted user. This affects the clients installed by customers when accessing a WebEx meeting. The following client builds of Cisco WebEx Business Suite (WBS30, WBS31, and WBS32), Cisco WebEx Meetings, and Cisco WebEx Meetings Server are impacted: Cisco WebEx Business Suite (WBS31) client builds prior to T31.23.2, Cisco WebEx Business Suite (WBS32) client builds prior to T32.10, Cisco WebEx Meetings with client builds prior to T32.10, Cisco WebEx Meetings Server builds prior to 2.8 MR2. Cisco Bug IDs: CSCvg19384, CSCvi10746.
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Analysis
by VulDB Data Team • 03/03/2023
This vulnerability represents a critical security flaw in Cisco WebEx communication platforms that affects multiple client versions and server implementations. The vulnerability stems from inadequate input validation mechanisms within the Cisco WebEx clients, specifically when processing file-sharing capabilities during meetings. Attackers can exploit this weakness by crafting malicious Flash (.swf) files and distributing them to meeting participants who are using vulnerable client versions. The flaw exists in the file handling process where the system fails to properly validate or sanitize incoming Flash content before execution, creating a pathway for remote code execution attacks. This vulnerability impacts organizations that rely on Cisco WebEx for business meetings and collaboration, as the attack vector can be initiated through legitimate meeting file sharing features.
The technical implementation of this vulnerability aligns with common software security principles where input validation failures create opportunities for code injection attacks. The flaw specifically affects the client-side processing of Flash files, which are commonly used for rich media presentations and interactive content within WebEx meetings. When a user opens a malicious SWF file shared through the WebEx platform, the vulnerable client executes the embedded code without proper sandboxing or security checks. This represents a classic example of insufficient input validation as classified under CWE-20, which encompasses weaknesses where input is not properly validated before being processed by applications. The vulnerability is particularly dangerous because it requires only a single authenticated user to be convinced to open a malicious file, making it a significant vector for social engineering attacks within corporate environments.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with complete system compromise capabilities. Successful exploitation allows remote attackers to execute arbitrary code with the privileges of the targeted user, potentially leading to full system control, data exfiltration, or establishment of persistent backdoors. Organizations using affected WebEx clients face significant risk as the attack can be initiated through legitimate meeting participation without requiring special privileges or advanced technical skills from the attacker. The vulnerability affects the entire WebEx ecosystem including business suite clients, standard meetings clients, and server implementations, making it a widespread concern across different deployment scenarios. This creates cascading security implications for enterprises that depend on WebEx for business continuity and collaboration, as compromise of a single user's system can potentially lead to broader network infiltration.
Organizations should immediately implement mitigation strategies including prompt patching of affected client versions and server builds to address the vulnerability. Cisco released specific updates for the affected builds including T31.23.2 for WBS31, T32.10 for WBS32, and server builds prior to 2.8 MR2. Additional protective measures should include network monitoring for suspicious Flash file transfers and implementing strict content filtering policies for file sharing within WebEx meetings. Security teams should also consider disabling Flash content execution in WebEx clients where possible and implementing user education programs to recognize potentially malicious file attachments. The vulnerability demonstrates the importance of proper input validation and sandboxing mechanisms in collaborative software platforms, aligning with ATT&CK framework techniques related to execution through legitimate user processes and privilege escalation through compromised client applications. Organizations must also review their incident response procedures to ensure rapid detection and containment of potential exploitation attempts targeting this vulnerability.