High

Entropy Backdoor in text-qrcode

  • Disclosed: 01.09.2020
  • Updated: 11.10.2026 10:22

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.

Affected software

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PlatformPackageVulnerable versionsFixed in
npm package text-qrcode >= 0.0.0 no fix

References

CVSS score 9.8/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-506
Platform
npm
Package
text-qrcode
Disclosed
01.09.2020
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-h5vj-f7r9-w564 - CC BY 4.0

Vulnerability history: text-qrcode

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

This is the only known vulnerability of this package.

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