# CVE-2021-34716: Cisco Expressway Series and TelePresence Video Communication Server Remote Code Execution Vulnerability

> Authenticated administrators can upload crafted software images to execute arbitrary code as root on Cisco Expressway and VCS devices.

- **Severity:** Medium 6.7 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Aug 2021
- **Updated:** 7 Nov 2024
- **Also known as:** GHSA-9mxr-mcvr-5xpm

## What is CVE-2021-34716?

CVE-2021-34716 is a medium-severity vulnerability in Cisco TelePresence Video Communication Server (VCS) Expressway, published on 18 Aug 2021. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

A vulnerability in the web-based management interface of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an authenticated, remote attacker to execute arbitrary code on the underlying operating system as the root user. This vulnerability is due to incorrect handling of certain crafted software images that are uploaded to the affected device. An attacker could exploit this vulnerability by authenticating to the system as an administrative user and then uploading specific crafted software images to the affected device. A successful exploit could allow the attacker to execute arbitrary code on the underlying operating system as the root user.

Weakness: CWE-755 (Improper Handling of Exceptional Conditions), CWE-460 (Improper Cleanup on Thrown Exception)

## Which versions are affected by CVE-2021-34716?

It affects 2 products.


Products: Cisco Expressway, Cisco Telepresence Video Communication Server.

## How do I fix CVE-2021-34716?

No fix has been published for CVE-2021-34716 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-34716 being exploited?

There is no known exploitation of CVE-2021-34716 in the wild and no public exploit code.

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

- [CVE-2024-20252](https://insights.sbomify.com/CVE-2024-20252/): Cross-site request forgery in Cisco TelePresence Video Communication Server (VCS) Expressway (critical 9.6)
- [CVE-2024-20254](https://insights.sbomify.com/CVE-2024-20254/): Cross-site request forgery in Cisco TelePresence Video Communication Server (VCS) Expressway (critical 9.6)
- [CVE-2022-20812](https://insights.sbomify.com/CVE-2022-20812/): Cisco Expressway Series and Cisco TelePresence Video Communication Server Vulnerabilities (critical 9.0)
- [CVE-2022-20813](https://insights.sbomify.com/CVE-2022-20813/): Cisco Expressway Series and Cisco TelePresence Video Communication Server Vulnerabilities (critical 9.0)
- [CVE-2017-3790](https://insights.sbomify.com/CVE-2017-3790/): Denial of service in Cisco Expressway Series Software and Cisco TelePresence VCS Software All versions prior to version X8.8.2 are vulnerable (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-34716 and fix it if it is affected.

What it is: CVE-2021-34716 is a medium-severity vulnerability in Cisco TelePresence Video Communication Server (VCS) Expressway, published on 18 Aug 2021. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-34716 in the wild and no public exploit code.

Affected product: Cisco TelePresence Video Communication Server (VCS) Expressway. 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-2021-34716/ (Markdown: https://insights.sbomify.com/CVE-2021-34716/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-34716
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-34716
- OSV: https://osv.dev/vulnerability/CVE-2021-34716

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-34716/
Summaries are generated and may contain mistakes; the official description above is the record.