TI-2020-03136 Aliases CVE-2020-3596 GHSA-9c7p-6wrp-cw32

Cisco Expressway Series and TelePresence Video Communication Server Denial of Service Vulnerability

LOW 35CWE-789Published 2020-10-08 · Updated 2024-11-13

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-789.

Summary

A vulnerability in the Session Initiation Protocol (SIP) of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to incorrect handling of incoming SIP traffic. An attacker could exploit this vulnerability by sending a series of SIP packets to an affected device. A successful exploit could allow the attacker to exhaust memory on an affected device, causing it to crash and leading to a DoS condition.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.01228 69th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Cisco	Cisco TelePresence Video Communication Server (VCS) Expressway	all versions	—	No fix listed	CNA

Cisco TelePresence Video Communication Server (VCS) Expressway VendorCisco Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPE	Versions	Role	Vendor
cpe:2.3:a:cisco:expressway::::::::	up to x12.6.3	Vulnerable	Cisco
cpe:2.3:a:cisco:telepresence_video_communication_server::::::::	up to x12.6.3	Vulnerable	Cisco

cpe:2.3:a:cisco:expressway:*:*:*:*:*:*:*:* Versions up to x12.6.3 Vulnerable ·Cisco
cpe:2.3:a:cisco:telepresence_video_communication_server:*:*:*:*:*:*:*:* Versions up to x12.6.3 Vulnerable ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2020-3596
2026-10-03 Alias added: GHSA-9c7p-6wrp-cw32

References

Advisory 1

20201007 Cisco Expressway Series and TelePresence Video Communication Server Denial of Service Vulnerability

TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
TI-2018-03923 Uncontrolled resource consumption in Linux Kernel CVSS 3.1HIGH 7.5
TI-2022-05371 Cisco Expressway Series and Cisco TelePresence Video Communication Server Vulnerabilities CVSS 3.1CRITICAL 9.0
TI-2024-13189 Cross-site request forgery in Cisco TelePresence Video Communication Server Expressway CVSS 3.1CRITICAL 9.6
TI-2024-13187 Cross-site request forgery in Cisco TelePresence Video Communication Server Expressway CVSS 3.1CRITICAL 9.6
TI-2022-05372 Cisco Expressway Series and Cisco TelePresence Video Communication Server Vulnerabilities CVSS 3.1CRITICAL 9.0

See all 13 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences