# CVE-2020-15173: Heap buffer overflow in ACCEL-PPP

> A heap buffer overflow in ACCEL-PPP allows remote attackers to execute arbitrary code or cause denial of service via crafted L2TP control packets.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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:** 9 Sep 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-rr68-fchr-69vf

## What is CVE-2020-15173?

CVE-2020-15173 is a high-severity memory corruption vulnerability in accel-ppp, published on 9 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In ACCEL-PPP (an implementation of PPTP/PPPoE/L2TP/SSTP), there is a buffer overflow when receiving an l2tp control packet ith an AVP which type is a string and no hidden flags, length set to less than 6. If your application is used in open networks or there are untrusted nodes in the network it is highly recommended to apply the patch. The problem was patched with commit 2324bcd5ba12cf28f47357a8f03cd41b7c04c52b As a workaround changes of commit 2324bcd5ba12cf28f47357a8f03cd41b7c04c52b can be applied to older versions.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2020-15173?

It affects 1 product.


Products: Accel-Ppp Accel-Ppp.

## How do I fix CVE-2020-15173?

No fix has been published for CVE-2020-15173 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-15173 being exploited?

There is no known exploitation of CVE-2020-15173 in the wild and no public exploit code.

## Other vulnerabilities in accel-ppp

- [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-2020-28194](https://insights.sbomify.com/CVE-2020-28194/): Integer overflow in n/a (critical 9.8)
- [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-2020-15173 and fix it if it is affected.

What it is: CVE-2020-15173 is a high-severity memory corruption vulnerability in accel-ppp, published on 9 Sep 2020. 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-2020-15173 in the wild and no public exploit code.

Affected product: accel-ppp. 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-2020-15173/ (Markdown: https://insights.sbomify.com/CVE-2020-15173/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-15173
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-15173
- OSV: https://osv.dev/vulnerability/CVE-2020-15173

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-15173/
Summaries are generated and may contain mistakes; the official description above is the record.