# OSV-2020-2320: UNKNOWN WRITE in cpu_arm_exec_arm

> A memory corruption vulnerability in QEMU's ARM emulator allows attackers to execute arbitrary code or cause denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Dec 2021

## What is OSV-2020-2320?

OSV-2020-2320 is a memory corruption vulnerability in unicorn, published on 4 Dec 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20220

```
Crash type: UNKNOWN WRITE
Crash state:
cpu_arm_exec_arm
tcg_exec_all_arm
qemu_tcg_cpu_loop
```

## Which versions are affected by OSV-2020-2320?

1 open source package ship an affected version, including unicorn.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `unicorn` | OSS-Fuzz | All versions | None |

## How do I fix OSV-2020-2320?

No fix has been published for OSV-2020-2320 yet. Limit exposure of the affected software until one is available.

## Is OSV-2020-2320 being exploited?

There is no known exploitation of OSV-2020-2320 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for OSV-2020-2320 and fix it if it is affected.

What it is: OSV-2020-2320 is a memory corruption vulnerability in unicorn, published on 4 Dec 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 OSV-2020-2320 in the wild and no public exploit code.

Affected packages and fixed versions:
- unicorn (OSS-Fuzz): affected all versions; no fix listed

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/OSV-2020-2320/ (Markdown: https://insights.sbomify.com/OSV-2020-2320/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/OSV-2020-2320

---
From sbomify Insights: https://insights.sbomify.com/OSV-2020-2320/
Summaries are generated and may contain mistakes; the official description above is the record.