CVE-2018-15420 in WebEx Network Recording Player
Summary
by MITRE
A vulnerability in the Cisco Webex Network Recording Player for Microsoft Windows and the Cisco Webex Player for Microsoft Windows could allow an attacker to execute arbitrary code on an affected system. The vulnerability exist because the affected software improperly validates Advanced Recording Format (ARF) and Webex Recording Format (WRF) files. An attacker could exploit this vulnerability by sending a user a malicious ARF or WRF file via a link or an email attachment and persuading the user to open the file by using the affected software. A successful exploit could allow the attacker to execute arbitrary code on the affected system.
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Analysis
by VulDB Data Team • 05/22/2023
The vulnerability identified as CVE-2018-15420 represents a critical code execution flaw in Cisco Webex Network Recording Player and Cisco Webex Player software for Microsoft Windows platforms. This security weakness stems from inadequate input validation mechanisms within the affected applications when processing Advanced Recording Format and Webex Recording Format files. The flaw creates a dangerous attack surface where malicious actors can leverage specially crafted file formats to compromise target systems. The vulnerability specifically affects the file parsing and handling mechanisms that process ARF and WRF multimedia files, which are commonly used for recording and sharing web conferencing sessions within Cisco Webex environments. The improper validation occurs at the file format parser level, where the software fails to adequately sanitize or verify the structure and content of these recording files before processing them.
The exploitation of this vulnerability requires social engineering techniques to trick users into opening maliciously crafted ARF or WRF files through email attachments or web links. This attack vector aligns with common phishing methodologies and demonstrates the intersection of file format vulnerabilities with user interaction requirements. When a user opens a malicious file with the affected software, the flawed validation logic allows arbitrary code execution with the privileges of the user running the application. The attack chain typically begins with the delivery of the malicious file through deceptive means, followed by user interaction to open the file, which triggers the code execution payload. This vulnerability effectively bypasses traditional security controls by leveraging legitimate software functionality to deliver malicious payloads, making it particularly dangerous in enterprise environments where users frequently interact with multimedia content.
The operational impact of CVE-2018-15420 extends beyond simple privilege escalation to encompass full system compromise capabilities. Successful exploitation enables attackers to execute arbitrary code on target systems, potentially leading to data exfiltration, lateral movement, persistent access, and complete system control. The vulnerability affects organizations that rely on Cisco Webex for collaboration and meeting recording functionality, creating widespread exposure across enterprise networks. Security teams must consider the implications of this vulnerability in relation to the ATT&CK framework, specifically under the execution and privilege escalation tactics where adversaries leverage legitimate software to establish footholds. The flaw also relates to CWE-129, which addresses improper validation of input boundaries, and CWE-749, which covers exposed dangerous method or function, as the vulnerable software exposes functionality that can be manipulated to execute unauthorized code.
Mitigation strategies for CVE-2018-15420 should prioritize immediate software updates from Cisco, which would include patches addressing the input validation flaws in the affected file processing modules. Organizations must implement network-based controls such as email filtering and web proxy restrictions to prevent access to potentially malicious ARF and WRF files from untrusted sources. Security awareness training programs should emphasize the dangers of opening unexpected email attachments or clicking suspicious links, particularly those related to collaboration software. System administrators should consider disabling or restricting the execution of the affected software in high-risk environments, while implementing application whitelisting policies to prevent unauthorized file execution. The vulnerability also highlights the importance of secure coding practices and proper input validation as outlined in industry standards such as the OWASP Top Ten and NIST cybersecurity guidelines, particularly concerning the prevention of injection attacks and improper input handling in multimedia processing applications.