# GHSA-8655-xgh5-5vvq: fast-fault has a segmentation fault due to lack of bound check

> An attacker can cause a segmentation fault and denial of service by providing an empty string to the fast-float library due to missing bounds checks.

- **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:** 13 Jan 2025
- **Also known as:** RUSTSEC-2025-0003

## What is GHSA-8655-xgh5-5vvq?

GHSA-8655-xgh5-5vvq is a memory corruption vulnerability in fast-float, published on 13 Jan 2025. 

### Official description

In this case, the "fast_float::common::AsciiStr::first" method within the "AsciiStr" struct 
uses the unsafe keyword to reading from memory without performing bounds checking. 
Specifically, it directly dereferences a pointer offset by "self.ptr".
Because of the above reason, the method accesses invalid memory address when it takes an empty string as its input.
This approach violates Rust’s memory safety guarantees, as it can lead to invalid memory access if empty buffer is provided.

No patched version for fast-float crate has been released, but a patch is available in the fast-float2 fork.

## Which versions are affected by GHSA-8655-xgh5-5vvq?

3 open source packages ship an affected version, including fast-float.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `fast-float` | crates.io | All versions to 0.2.0 | None |
| `fast-float` | crates.io | All versions to 0.2.0 | None |
| `fast-float` | crates.io | From 0.0.0-0 | None |

## How do I fix GHSA-8655-xgh5-5vvq?

No fix has been published for GHSA-8655-xgh5-5vvq yet. Limit exposure of the affected software until one is available.

## Is GHSA-8655-xgh5-5vvq being exploited?

There is no known exploitation of GHSA-8655-xgh5-5vvq in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-8655-xgh5-5vvq and fix it if it is affected.

What it is: GHSA-8655-xgh5-5vvq is a memory corruption vulnerability in fast-float, published on 13 Jan 2025. 
Exploitation: There is no known exploitation of GHSA-8655-xgh5-5vvq in the wild and no public exploit code.

Affected packages and fixed versions:
- fast-float (crates.io): affected all versions up to 0.2.0; no fix listed
- fast-float (crates.io): affected all versions up to 0.2.0; no fix listed
- fast-float (crates.io): affected from 0.0.0-0; 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/GHSA-8655-xgh5-5vvq/ (Markdown: https://insights.sbomify.com/GHSA-8655-xgh5-5vvq/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-8655-xgh5-5vvq

---
From sbomify Insights: https://insights.sbomify.com/GHSA-8655-xgh5-5vvq/
Summaries are generated and may contain mistakes; the official description above is the record.