CVE-2018-0264 in WebEx Network Recording Player
Summary
by MITRE
A vulnerability in the Cisco WebEx Network Recording Player for Advanced Recording Format (ARF) files could allow an unauthenticated, remote attacker to execute arbitrary code on the system of a targeted user. An attacker could exploit this vulnerability by sending the user a link or email attachment with a malicious ARF file and persuading the user to follow the link or open the file. Successful exploitation could allow the attacker to execute arbitrary code on the user's system. This vulnerability affects Cisco WebEx Business Suite meeting sites, Cisco WebEx Meetings sites, Cisco WebEx Meetings Server, and Cisco WebEx ARF players. The following client builds of Cisco WebEx Business Suite (WBS31 and WBS32), Cisco WebEx Meetings, and Cisco WebEx Meetings Server are affected: Cisco WebEx Business Suite (WBS31) client builds prior to T31.23.4, Cisco WebEx Business Suite (WBS32) client builds prior to T32.12, Cisco WebEx Meetings with client builds prior to T32.12, Cisco WebEx Meeting Server builds prior to 3.0 Patch 1. Cisco Bug IDs: CSCvh85410, CSCvh85430, CSCvh85440, CSCvh85442, CSCvh85453, CSCvh85457.
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Analysis
by VulDB Data Team • 02/02/2020
This vulnerability resides within the Cisco WebEx Network Recording Player's handling of Advanced Recording Format files, representing a classic buffer overflow condition that enables remote code execution. The flaw manifests when the player processes maliciously crafted ARF files, specifically through improper input validation and memory management during file parsing operations. The vulnerability operates at the application layer and requires no authentication, making it particularly dangerous as attackers can exploit it through simple social engineering tactics such as phishing emails or malicious links. The attack vector leverages user interaction with compromised files, making it a prime example of a client-side exploit that bypasses traditional network security controls by targeting end-user systems directly.
The technical implementation of this vulnerability stems from insufficient bounds checking within the ARF file parser component of Cisco WebEx applications. When processing malformed ARF files, the application fails to properly validate the size and structure of data elements, leading to memory corruption that can be leveraged to overwrite critical program execution pointers. This type of vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The exploitation mechanism typically involves crafting a malicious ARF file that triggers memory corruption during parsing, allowing attackers to inject and execute arbitrary code within the context of the user's session. The vulnerability affects multiple Cisco WebEx platforms including Business Suite, Meetings sites, and Meetings Server, indicating a widespread impact across the product line.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with persistent access to targeted systems through the WebEx application. Successful exploitation enables attackers to perform actions such as installing malware, modifying system configurations, accessing sensitive data, or establishing persistence mechanisms within the victim environment. The vulnerability's remote nature means that attackers can compromise systems without requiring physical access or network-level privileges, making it particularly attractive for large-scale campaigns. Organizations using affected Cisco WebEx versions face significant risk as the vulnerability can be exploited through standard communication channels, including email attachments and web links, potentially affecting thousands of users across different network segments. This vulnerability directly maps to ATT&CK technique T1059.007 for Command and Scripting Interpreter, and T1068 for Exploitation for Privilege Escalation.
Mitigation strategies for this vulnerability should focus on immediate patch deployment across all affected Cisco WebEx installations, particularly targeting the specific client builds mentioned in the vulnerability description. Organizations should implement network-level controls such as email filtering and web proxy restrictions to prevent access to malicious ARF files, while also conducting user awareness training to recognize potential social engineering attempts. The vulnerability's nature makes it critical to maintain updated security software and monitoring systems that can detect anomalous behavior associated with code execution attempts. Additionally, administrators should consider implementing application whitelisting policies that restrict execution of untrusted ARF files, and establish incident response procedures specifically addressing remote code execution vulnerabilities in collaboration platforms. Regular vulnerability assessments of WebEx environments and other collaboration tools should be conducted to identify similar weaknesses in other enterprise applications.