# OSV-2021-710: Heap-use-after-free in iov_from_buf_full

> A heap-use-after-free in the Linux kernel's virtio-net driver allows attackers to cause denial of service or potentially execute code via crafted network packets.

- **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:** 1 May 2021

## What is OSV-2021-710?

OSV-2021-710 is an use after free vulnerability in qemu, published on 1 May 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=33785

```
Crash type: Heap-use-after-free WRITE 2
Crash state:
iov_from_buf_full
iov_from_buf
virtio_net_receive_rcu
```

## Which versions are affected by OSV-2021-710?

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


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

## How do I fix OSV-2021-710?

No fix has been published for OSV-2021-710 yet. Limit exposure of the affected software until one is available.

## Is OSV-2021-710 being exploited?

There is no known exploitation of OSV-2021-710 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for OSV-2021-710 and fix it if it is affected.

What it is: OSV-2021-710 is an use after free vulnerability in qemu, published on 1 May 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-2021-710 in the wild and no public exploit code.

Affected packages and fixed versions:
- qemu (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-2021-710/ (Markdown: https://insights.sbomify.com/OSV-2021-710/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/OSV-2021-710

---
From sbomify Insights: https://insights.sbomify.com/OSV-2021-710/
Summaries are generated and may contain mistakes; the official description above is the record.