# CVE-2021-28186: ASUS BMC's firmware: buffer overflow - ActiveX configuration-2 acquisition

> Remote attackers can cause a buffer overflow in ASUS BMC firmware, leading to abnormal termination of the web service and denial of service.

- **Severity:** Medium 4.9 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/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:** 6 Apr 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-8p5w-j26w-7656

## What is CVE-2021-28186?

CVE-2021-28186 is a medium-severity memory corruption vulnerability in ASUS BMC firmware for ASMB8-iKVM, published on 6 Apr 2021. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

The specific function in ASUS BMC’s firmware Web management page (ActiveX configuration-2 acquisition) does not verify the string length entered by users, resulting in a Buffer overflow vulnerability. As obtaining the privileged permission, remote attackers use the leakage to abnormally terminate the Web service.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2021-28186?

It affects 3 products.


Products: Asus Asmb8-Ikvm Firmware, Asus Z10pe-D16 Ws Firmware, Asus Z10pr-D16 Firmware.

## How do I fix CVE-2021-28186?

No fix has been published for CVE-2021-28186 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-28186 being exploited?

There is no known exploitation of CVE-2021-28186 in the wild and no public exploit code.

## Other vulnerabilities in ASUS BMC firmware for ASMB8-iKVM

- [CVE-2023-26602](https://insights.sbomify.com/CVE-2023-26602/): Command injection in n/a (critical 9.8)
- [CVE-2021-28203](https://insights.sbomify.com/CVE-2021-28203/): ASUS BMC's firmware: command injection - Web Set Media Image function (high 7.2)
- [CVE-2021-28204](https://insights.sbomify.com/CVE-2021-28204/): ASUS BMC's firmware: command injection - Modify user’s information function (high 7.2)
- [CVE-2021-28175](https://insights.sbomify.com/CVE-2021-28175/): ASUS BMC's firmware: buffer overflow - Radius configuration function (medium 4.9)
- [CVE-2021-28176](https://insights.sbomify.com/CVE-2021-28176/): ASUS BMC's firmware: buffer overflow - DNS configuration function (medium 4.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-28186 and fix it if it is affected.

What it is: CVE-2021-28186 is a medium-severity memory corruption vulnerability in ASUS BMC firmware for ASMB8-iKVM, published on 6 Apr 2021. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-28186 in the wild and no public exploit code.

Affected product: ASUS BMC firmware for ASMB8-iKVM. 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-2021-28186/ (Markdown: https://insights.sbomify.com/CVE-2021-28186/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-28186
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-28186
- OSV: https://osv.dev/vulnerability/CVE-2021-28186

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-28186/
Summaries are generated and may contain mistakes; the official description above is the record.