# OSV-2021-330: Heap-buffer-overflow in bn_sqr_karat_imp

> A heap-buffer-overflow in the Relic library's big number squaring function allows attackers to cause crashes or potentially execute code.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Not stated
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Feb 2021

## What is OSV-2021-330?

OSV-2021-330 is a memory corruption vulnerability in relic, published on 9 Feb 2021. 

### Official description

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=30537

```
Crash type: Heap-buffer-overflow WRITE 8
Crash state:
bn_sqr_karat_imp
bn_sqr_karat
cryptofuzz::module::relic_bignum::Sqr::Run
```

## Which versions are affected by OSV-2021-330?

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


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

## How do I fix OSV-2021-330?

No fix has been published for OSV-2021-330 yet. Limit exposure of the affected software until one is available.

## Is OSV-2021-330 being exploited?

There is no known exploitation of OSV-2021-330 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for OSV-2021-330 and fix it if it is affected.

What it is: OSV-2021-330 is a memory corruption vulnerability in relic, published on 9 Feb 2021. 
Exploitation: There is no known exploitation of OSV-2021-330 in the wild and no public exploit code.

Affected packages and fixed versions:
- relic (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-2021-330/ (Markdown: https://insights.sbomify.com/OSV-2021-330/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/OSV-2021-330

---
From sbomify Insights: https://insights.sbomify.com/OSV-2021-330/
Summaries are generated and may contain mistakes; the official description above is the record.