Cisco WebEx Recording Format Player contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code or cause a denial of service condition.
A vulnerability in the Cisco WebEx Recording Format (WRF) player used in Cisco WebEx Business Suite could allow an unauthenticated, remote attacker to crash the Cisco WebEx WRF player, and in some cases execute remote code with the privilege of the logged in user.
The vulnerability is due to a failure to properly validate input from the .wrf recording being played. An attacker could exploit this vulnerability by persuading a user to play a specially crafted .wrf recording in a vulnerable Cisco WebEx WRF player. This vulnerability cannot be triggered by just attending a WebEx meeting.
Cisco would like to thank the Microsoft Vulnerability Research (MSVR) team for reporting this vulnerability.
Cisco has confirmed the vulnerability in a security advisory and released software updates.
Cisco WebEx WRF players running on Microsoft Windows, Apple Mac OS X, and Linux platforms with the following client builds are vulnerable:
Cisco WebEx Business Suite client builds prior to T28.8 (28.8)
Cisco WebEx Business Suite client builds prior to T27LDSP32EP16 (27.32.16)
The vulnerability cannot be triggered by users attending a WebEx session. To exploit the vulnerability, an attacker must convince a user to play a malicious .wrf file. The attacker may provide a file to the user and persuade the user to open or execute the file by using misleading language or instructions.
Cisco indicates through the CVSS score that proof-of-concept code exists; however, the code is not known to be publicly available.
An unauthenticated, remote attacker could exploit this vulnerability to execute arbitrary code on a targeted system with the privileges of the user. If the user holds elevated privileges, a successful exploit could result in a complete compromise of the system. An attacker could also cause an affected application to crash, resulting in a denial of service (DoS) condition.
The vulnerability is due to improper processing of .wrf files by the affected software.
An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to open a crafted .wrf file with the affected application. Processing the malicious file may trigger a stack-based overflow condition that may allow the attacker to execute arbitrary code or cause the affected application to crash, resulting in a DoS condition.
Administrators are advised to apply the appropriate updates.
Users are advised not to open email messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in email messages are safe, they are advised not to open them.
Users are advised not to open media files from suspicious or unrecognized sources. If users cannot verify that media files are safe, they are advised not to open them.
Administrators are advised to monitor critical systems.
Cisco customers could receive automatic updates after a recording file that is hosted on a WebEx server is accessed. In addition, customers that installed the Cisco WebEx WRF Player manually could perform a manual install of a new version of the WebEx WRF Player at the following link: WebEx
The urgency and severity ratings of this alert are not tailored to individual users; users may value alerts differently based upon their network configurations and circumstances. THE ALERT, AND INFORMATION CONTAINED THEREIN, ARE PROVIDED ON AN "AS IS" BASIS AND DO NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE ALERT, AND INFORMATION CONTAINED THEREIN, OR MATERIALS LINKED FROM THE ALERT, IS AT YOUR OWN RISK. INFORMATION IN THIS ALERT AND ANY RELATED COMMUNICATIONS IS BASED ON OUR KNOWLEDGE AT THE TIME OF PUBLICATION AND IS SUBJECT TO CHANGE WITHOUT NOTICE. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.