# CVE-2020-8939: Out of Bounds read in Asylo

> An out-of-bounds read in Asylo allows attackers to read memory from the enclave heap via the inet_ntop function.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N`)
- **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:** 15 Dec 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-8mgg-4h42-8rj6

## What is CVE-2020-8939?

CVE-2020-8939 is a medium-severity memory corruption vulnerability in Google LLC Asylo, published on 15 Dec 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An out of bounds read on the enc_untrusted_inet_ntop function allows an attack to extend the result size that is used by memcpy() to read memory from within the enclave heap. We recommend upgrading past commit 6ff3b77ffe110a33a2f93848a6333f33616f02c4

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2020-8939?

It affects 1 product.


Products: Google Asylo.

## How do I fix CVE-2020-8939?

No fix has been published for CVE-2020-8939 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-8939 being exploited?

There is no known exploitation of CVE-2020-8939 in the wild and no public exploit code.

## Other vulnerabilities in Google LLC Asylo

- [CVE-2021-22548](https://insights.sbomify.com/CVE-2021-22548/): Arbitrary enclave memory overread vulnerability in Asylo TrustedPrimitives::UntrustedCall (medium 6.5)
- [CVE-2021-22549](https://insights.sbomify.com/CVE-2021-22549/): Arbitrary enclave memory overwrite vulnerability in Asylo TrustedPrimitives::UntrustedCall (medium 6.5)
- [CVE-2021-22550](https://insights.sbomify.com/CVE-2021-22550/): Enclave memory overwrite/overread vulnerability in Asylo UntrustedCacheMalloc::GetBuffer (medium 6.5)
- [CVE-2020-8904](https://insights.sbomify.com/CVE-2020-8904/): Arbitrary trusted memory overwrite vulnerability in Asylo (medium 6.4)
- [CVE-2021-22552](https://insights.sbomify.com/CVE-2021-22552/): Memory overread secure enclave in Asylo 0.6.2 (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-8939 and fix it if it is affected.

What it is: CVE-2020-8939 is a medium-severity memory corruption vulnerability in Google LLC Asylo, published on 15 Dec 2020. 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-2020-8939 in the wild and no public exploit code.

Affected product: Google LLC Asylo. 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-2020-8939/ (Markdown: https://insights.sbomify.com/CVE-2020-8939/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-8939
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-8939
- OSV: https://osv.dev/vulnerability/CVE-2020-8939

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-8939/
Summaries are generated and may contain mistakes; the official description above is the record.