# CVE-2020-28194: Integer overflow in n/a

> An integer underflow in accel-ppp allows arbitrary code execution if an attacker controls the RADIUS server.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Feb 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-2m44-rh3c-x4gr

## What is CVE-2020-28194?

CVE-2020-28194 is a critical vulnerability in n/a, published on 1 Feb 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Variable underflow exists in accel-ppp radius/packet.c when receiving a RADIUS vendor-specific attribute with length field is less than 2. It has an impact only when the attacker controls the RADIUS server, which can lead to arbitrary code execution.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound))

## Which versions are affected by CVE-2020-28194?

It affects 1 product.


Products: Accel-Ppp Accel-Ppp.

## How do I fix CVE-2020-28194?

No fix has been published for CVE-2020-28194 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-28194 being exploited?

There is no known exploitation of CVE-2020-28194 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2022-0982](https://insights.sbomify.com/CVE-2022-0982/): Buffer Overflow via crafted client request in Accel-PPP v1.12 (critical 9.8)
- [CVE-2022-24704](https://insights.sbomify.com/CVE-2022-24704/): Buffer Overflow via Crafted IPv6 Addr Attribute Type Client Request in Accel-PPP v1.12 (critical 9.8)
- [CVE-2022-24705](https://insights.sbomify.com/CVE-2022-24705/): Buffer Overflow via Crafted Ipv6 Prefix Attribute Type Client Request in accel-ppp v1.12 (critical 9.8)
- [CVE-2020-15173](https://insights.sbomify.com/CVE-2020-15173/): Heap buffer overflow in ACCEL-PPP (high 8.2)
- [CVE-2021-42870](https://insights.sbomify.com/CVE-2021-42870/): Memory corruption in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-28194 and fix it if it is affected.

What it is: CVE-2020-28194 is a critical vulnerability in n/a, published on 1 Feb 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-28194 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-2020-28194/ (Markdown: https://insights.sbomify.com/CVE-2020-28194/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-28194
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-28194
- OSV: https://osv.dev/vulnerability/CVE-2020-28194

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-28194/
Summaries are generated and may contain mistakes; the official description above is the record.