# CVE-2021-34758: Cisco TelePresence Collaboration Endpoint and RoomOS Software Denial of Service Vulnerability

> An authenticated local attacker can corrupt shared memory to cause a denial of service on Cisco RoomOS devices.

- **Severity:** Medium 4.4 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Oct 2021
- **Updated:** 7 Nov 2024
- **Also known as:** GHSA-m9hj-8j64-3cfq

## What is CVE-2021-34758?

CVE-2021-34758 is a medium-severity denial of service vulnerability in Cisco RoomOS Software, published on 6 Oct 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability in the memory management of Cisco TelePresence Collaboration Endpoint (CE) Software and Cisco RoomOS Software could allow an authenticated, local attacker to corrupt a shared memory segment, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient access controls to a shared memory resource. An attacker could exploit this vulnerability by corrupting a shared memory segment on an affected device. A successful exploit could allow the attacker to cause the device to reload. The device will recover from the corruption upon reboot.

Weakness: CWE-732 (Incorrect Permission Assignment for Critical Resource)

## Which versions are affected by CVE-2021-34758?

It affects 2 products.


Products: Cisco Roomos, Cisco Telepresence Collaboration Endpoint.

## How do I fix CVE-2021-34758?

No fix has been published for CVE-2021-34758 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-34758 being exploited?

There is no known exploitation of CVE-2021-34758 in the wild and no public exploit code.

## Other vulnerabilities in Cisco RoomOS Software

- [CVE-2026-20150](https://insights.sbomify.com/CVE-2026-20150/): Cisco RoomOS Security Hardening Release - Access Control Vulnerabilities (high 8.8)
- [CVE-2019-15288](https://insights.sbomify.com/CVE-2019-15288/): Cisco TelePresence Collaboration Endpoint, TelePresence Codec, and RoomOS Software Privilege Escalation Vulnerability (high 8.8)
- [CVE-2026-20156](https://insights.sbomify.com/CVE-2026-20156/): Cisco RoomOS Security Hardening Release - Buffer Management Vulnerabilities (high 8.1)
- [CVE-2026-20153](https://insights.sbomify.com/CVE-2026-20153/): Cisco RoomOS Security Hardening Release - Input Validation Vulnerabilities (high 7.5)
- [CVE-2026-20157](https://insights.sbomify.com/CVE-2026-20157/): Cisco RoomOS Security Hardening Release - Missing Encryption Vulnerabilities (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-34758 and fix it if it is affected.

What it is: CVE-2021-34758 is a medium-severity denial of service vulnerability in Cisco RoomOS Software, published on 6 Oct 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-34758 in the wild and no public exploit code.

Affected product: Cisco RoomOS Software. 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-2021-34758/ (Markdown: https://insights.sbomify.com/CVE-2021-34758/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-34758
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-34758
- OSV: https://osv.dev/vulnerability/CVE-2021-34758

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-34758/
Summaries are generated and may contain mistakes; the official description above is the record.