# CVE-2021-22552: Memory overread secure enclave in Asylo 0.6.2

> An attacker can read memory from within the secure enclave by bypassing syscall validation, exposing sensitive data.

- **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:** 2 Aug 2021
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-wjwj-7rpq-5gg8

## What is CVE-2021-22552?

CVE-2021-22552 is a medium-severity vulnerability in Google LLC Asylo, published on 2 Aug 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An untrusted memory read vulnerability in Asylo versions up to 0.6.1 allows an untrusted attacker to pass a syscall number in MessageReader that is then used by sysno() and can bypass validation. This can allow the attacker to read memory from within the secure enclave. We recommend updating to Asylo 0.6.3 or past https://github.com/google/asylo/commit/90d7619e9dd99bcdb6cd28c7649d741d254d9a1a

Weakness: CWE-125 (Out-of-bounds Read), CWE-126 (Buffer Over-read)

## Which versions are affected by CVE-2021-22552?

It affects 1 product.


Products: Google Asylo.

## How do I fix CVE-2021-22552?

No fix has been published for CVE-2021-22552 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-22552 being exploited?

There is no known exploitation of CVE-2021-22552 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-2020-8935](https://insights.sbomify.com/CVE-2020-8935/): Memory corruption in Asylo (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-22552 and fix it if it is affected.

What it is: CVE-2021-22552 is a medium-severity vulnerability in Google LLC Asylo, published on 2 Aug 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-2021-22552 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-2021-22552/ (Markdown: https://insights.sbomify.com/CVE-2021-22552/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-22552
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-22552
- OSV: https://osv.dev/vulnerability/CVE-2021-22552

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-22552/
Summaries are generated and may contain mistakes; the official description above is the record.