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

> Authenticated attackers can cause a denial of service by sending crafted XML payloads to Cisco Expressway or VCS systems.

- **Severity:** Medium 6.8 (`CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Apr 2019
- **Updated:** 21 Nov 2024
- **Also known as:** GHSA-w82q-5jhx-c75p

## What is CVE-2019-1720?

CVE-2019-1720 is a medium-severity denial of service vulnerability in Cisco TelePresence Video Communication Server (VCS), published on 18 Apr 2019. An attacker needs administrator access to exploit it, with no action from the victim.

### Official 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.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2019-1720?

It affects 1 product.


Products: Cisco Telepresence Video Communication Server.

## How do I fix CVE-2019-1720?

No fix has been published for CVE-2019-1720 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-1720 being exploited?

There is no known exploitation of CVE-2019-1720 in the wild and no public exploit code.

## Other vulnerabilities in Cisco TelePresence Video Communication Server (VCS)

- [CVE-2023-20105](https://insights.sbomify.com/CVE-2023-20105/): Privilege escalation in Cisco TelePresence Video Communication Server (VCS) Expressway (critical 9.6)
- [CVE-2023-20192](https://insights.sbomify.com/CVE-2023-20192/): Cisco Expressway Series and Cisco TelePresence Video Communication Server Privilege Escalation Vulnerabilities (critical 9.6)
- [CVE-2022-20754](https://insights.sbomify.com/CVE-2022-20754/): Cisco Expressway Series and Cisco TelePresence Video Communication Server Vulnerabilities (critical 9.0)
- [CVE-2022-20755](https://insights.sbomify.com/CVE-2022-20755/): Cisco Expressway Series and Cisco TelePresence Video Communication Server Vulnerabilities (critical 9.0)
- [CVE-2016-1468](https://insights.sbomify.com/CVE-2016-1468/): Command injection in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-1720 and fix it if it is affected.

What it is: CVE-2019-1720 is a medium-severity denial of service vulnerability in Cisco TelePresence Video Communication Server (VCS), published on 18 Apr 2019. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-1720 in the wild and no public exploit code.

Affected product: Cisco TelePresence Video Communication Server (VCS). No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2019-1720/ (Markdown: https://insights.sbomify.com/CVE-2019-1720/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-1720
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-1720
- OSV: https://osv.dev/vulnerability/CVE-2019-1720

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-1720/
Summaries are generated and may contain mistakes; the official description above is the record.