# CVE-2021-33478: Memory corruption in n/a

> An attacker with physical access can achieve arbitrary code execution in the TrustZone TEE of affected Cisco IP phones by manipulating chip pins.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Jul 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-vh28-q6j2-63w7

## What is CVE-2021-33478?

CVE-2021-33478 is a medium-severity memory corruption vulnerability in n/a, published on 22 Jul 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The TrustZone implementation in certain Broadcom MediaxChange firmware could allow an unauthenticated, physically proximate attacker to achieve arbitrary code execution in the TrustZone Trusted Execution Environment (TEE) of an affected device. This, for example, affects certain Cisco IP Phone and Wireless IP Phone products before 2021-07-07. Exploitation is possible only when the attacker can disassemble the device in order to control the voltage/current for chip pins.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2021-33478?

It affects 15 products.


Products: Cisco Ip Phone 8800 Firmware, Cisco Ip Phone 8800 Series With Multiplatform Firmware, Cisco Ip Phone 8811 Firmware, Cisco Ip Phone 8811 With Multiplatform Firmware, Cisco Ip Phone 8841 Firmware, Cisco Ip Phone 8841 With Multiplatform Firmware, Cisco Ip Phone 8845 Firmware, Cisco Ip Phone 8845 With Multiplatform Firmware, Cisco Ip Phone 8851 Firmware, Cisco Ip Phone 8851 With Multiplatform Firmware, Cisco Ip Phone 8861 Firmware, Cisco Ip Phone 8861 With Multiplatform Firmware, Cisco Ip Phone 8865 Firmware, Cisco Ip Phone 8865 With Multiplatform Firmware, Cisco Wireless Ip Phone 8821 Firmware.

## How do I fix CVE-2021-33478?

No fix has been published for CVE-2021-33478 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-33478 being exploited?

There is no known exploitation of CVE-2021-33478 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2019-1766](https://insights.sbomify.com/CVE-2019-1766/): Cisco IP Phone 8800 Series File Upload Denial of Service Vulnerability (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-33478 and fix it if it is affected.

What it is: CVE-2021-33478 is a medium-severity memory corruption vulnerability in n/a, published on 22 Jul 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-2021-33478 in the wild and no public exploit code.

Affected product: n/a. 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-2021-33478/ (Markdown: https://insights.sbomify.com/CVE-2021-33478/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-33478
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-33478
- OSV: https://osv.dev/vulnerability/CVE-2021-33478

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-33478/
Summaries are generated and may contain mistakes; the official description above is the record.