CVE-2017-3790: Cisco Expressway

High severity, CVSS 8.6. EPSS: 3.5% chance of exploitation in the next 30 days.

A vulnerability in the received packet parser of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) software could allow an unauthenticated, remote attacker to cause a reload of the affected system, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient size validation of user-supplied data. An attacker could exploit this vulnerability by sending crafted H.224 data in Real-Time Transport Protocol (RTP) packets in an H.323 call. An exploit could allow the attacker to overflow a buffer in a cache that belongs to the received packet parser, which will result in a crash of the application, resulting in a DoS condition. All versions of Cisco Expressway Series Software and Cisco TelePresence VCS Software prior to version X8.8.2 are vulnerable. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. Cisco Bug IDs: CSCus99263.

Affected products

• Cisco Expressway: version x8.1.0 only; version x8.1.1 only; version x8.1.2 only; version x8.1_base only; version x8.2.1 only; version x8.2.2 only; …
• Cisco Telepresence Video Communication Server: version x5.2_base only; version x6.0_base only; version x6.1_base only; version x7.0.0 only; version x7.0.1 only; version x7.0.2 only; …

Published 2017-02-01. Last modified 2026-06-17.