CVE-2019-15283: 
Cisco Webex Meetings vulnerability analysis and mitigation

CVE-2019-15283 is a memory corruption vulnerability discovered in the Cisco Webex Network Recording Player and Webex Player for Microsoft Windows. The vulnerability was disclosed on November 6, 2019, affecting multiple versions of Cisco Webex Meetings sites, Cisco Webex Meetings Online, and Cisco Webex Meetings Server. The vulnerability exists due to insufficient validation of certain elements within a Webex recording stored in Advanced Recording Format (ARF) files (Cisco Advisory, Fortinet Research).

The vulnerability is caused by insufficient validation of certain elements in ARF files, which leads to an out-of-bounds memory access. The issue received a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) and is classified under CWE-119 (Buffer Overflow). The vulnerability affects multiple versions of Cisco Webex software, including Webex Meetings releases prior to 39.5.12, Webex Meetings Online releases before 1.3.44, and Webex Meetings Server releases before 4.0MR2 (NVD).

If successfully exploited, this vulnerability could allow an attacker to execute arbitrary code on the affected system with the privileges of the targeted user. The impact is particularly severe as it could lead to complete system compromise within the context of the current user (Cisco Advisory, Fortinet Research).

An attacker could exploit this vulnerability by sending a user a malicious ARF file through a link or email attachment and persuading the user to open the file with the affected software on the local system. The exploitation requires user interaction, as the target must voluntarily open the malicious file. As of the disclosure, there were no reports of this vulnerability being exploited in the wild (Cisco Advisory).

Cisco released software updates to address this vulnerability. The fixed versions include Webex Meetings Release 39.5.12, Webex Meetings Online Release 1.3.44, and Webex Meetings Server Release 4.0MR2. No workarounds are available for this vulnerability, making it critical for users to update to the patched versions (Cisco Advisory).

The vulnerability was discovered by security researchers Kushal Arvind Shah and Yici Zhang from Fortinet's FortiGuard Labs. Fortinet had previously released an IPS signature named Cisco.WebEx.CVE-2019-15283.Memory.Corruption to proactively protect their customers (Fortinet Research, SecurityWeek).