Impact

fastify-bearer-auth does not securely use crypto.timingSafeEqual. A malicious attacker could estimate the length of one valid bearer token. According to the corresponding RFC 6750, the bearer token has only base64 valid characters, reducing the range of characters for a brute force attack.

All versions of fastify-bearer-auth are also affected.

Patches

We released:

• v8.0.1 with a fix for the Fastify v4 line
• v7.0.2 with a fix for the Fastify v3 line

Workarounds

There are no workarounds. Update your dependencies.

References

https://hackerone.com/reports/1633287

For more information

If you have any questions or comments about this advisory:

• Open an issue in https://github.com/fastify/fastify-bearer-auth
• Email us at hello@matteocollina.com