# GHSA-h5vj-f7r9-w564: Entropy Backdoor in text-qrcode

> A backdoor in the text-qrcode npm package weakens cryptographic entropy, allowing attackers to guess generated keys and compromise sensitive data.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Sep 2020

## What is GHSA-h5vj-f7r9-w564?

GHSA-h5vj-f7r9-w564 is a vulnerability in text-qrcode, published on 1 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

All versions of `text-qrcode` contain malicious code that overwrites the `randomBytes` method for the `crypto` module with a function that generates weak entropy. Instead of generating 32 bytes, the infected randomBytes will generate 3 bytes of entropy and hash them, resulting in a 32 byte value being returned, but one that is easily guessable. 

## Recommendation

Uninstall `text-qrcode` immediately. If the module was used to generate entropy that is load bearing, all such instances of generated entropy must be replaced. This includes things like bitcoin wallets, private keys, encrypted messages, etc.

## Which versions are affected by GHSA-h5vj-f7r9-w564?

2 open source packages ship an affected version, including text-qrcode.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `text-qrcode` | npm | From 0.0.0 | None |
| `text-qrcode` | npm | From 0.0.0 | None |

## How do I fix GHSA-h5vj-f7r9-w564?

No fix has been published for GHSA-h5vj-f7r9-w564 yet. Limit exposure of the affected software until one is available.

## Is GHSA-h5vj-f7r9-w564 being exploited?

There is no known exploitation of GHSA-h5vj-f7r9-w564 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-h5vj-f7r9-w564 and fix it if it is affected.

What it is: GHSA-h5vj-f7r9-w564 is a vulnerability in text-qrcode, published on 1 Sep 2020. 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-h5vj-f7r9-w564 in the wild and no public exploit code.

Affected packages and fixed versions:
- text-qrcode (npm): affected from 0.0.0; no fix listed
- text-qrcode (npm): affected from 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-h5vj-f7r9-w564/ (Markdown: https://insights.sbomify.com/GHSA-h5vj-f7r9-w564/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-h5vj-f7r9-w564

---
From sbomify Insights: https://insights.sbomify.com/GHSA-h5vj-f7r9-w564/
Summaries are generated and may contain mistakes; the official description above is the record.