# GHSA-9mfc-chwf-7whf: ckb: Large dep group requires a lot of resources to process but the cost to commit the transaction is very low.

> Attackers can cause resource exhaustion and denial of service by submitting transactions with large dependency groups, affecting CKB blockchain nodes.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Nov 2022

## What is GHSA-9mfc-chwf-7whf?

GHSA-9mfc-chwf-7whf is a denial of service vulnerability in ckb, published on 2 Nov 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

### Impact

When a transaction contains a dep group with many cells, the resources required to process it are not linear to the transaction size nor spent script cycles. 

### Patches

In 0.43.3, nodes drop the transactions relayed to them when they contain a dep group with more than 64 cells. They do not ban peers who send them such transactions.

In 0.100, the consensus disallow transactions using a dep group with more than 64 cells. Peers relaying such transaction must be banned. Blocks committing such transactions must be rejected.

## Which versions are affected by GHSA-9mfc-chwf-7whf?

2 open source packages ship an affected version, including ckb.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ckb` | crates.io | All versions | 0.43.3 |
| `ckb` | crates.io | All versions | 0.43.3 |

## How do I fix GHSA-9mfc-chwf-7whf?

Upgrade ckb to 0.43.3 or later.

## Is GHSA-9mfc-chwf-7whf being exploited?

There is no known exploitation of GHSA-9mfc-chwf-7whf in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-9mfc-chwf-7whf and fix it if it is affected.

What it is: GHSA-9mfc-chwf-7whf is a denial of service vulnerability in ckb, published on 2 Nov 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-9mfc-chwf-7whf in the wild and no public exploit code.

Affected packages and fixed versions:
- ckb (crates.io): affected all versions; fixed in 0.43.3
- ckb (crates.io): affected all versions; fixed in 0.43.3

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-9mfc-chwf-7whf/ (Markdown: https://insights.sbomify.com/GHSA-9mfc-chwf-7whf/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-9mfc-chwf-7whf

---
From sbomify Insights: https://insights.sbomify.com/GHSA-9mfc-chwf-7whf/
Summaries are generated and may contain mistakes; the official description above is the record.