CVE-2024-49364

描述

### Summary Private key can be extracted on signing a malicious JSON-stringifiable object, when global Buffer is [`buffer` package](https://www.npmjs.com/package/buffer) ### Details This affects only environments where `require('buffer')` is <https://npmjs.com/buffer> E.g.: browser bundles, React Native apps, etc. `Buffer.isBuffer` check can be bypassed, resulting in `k` reuse for different messages, leading to private key extraction over a single invalid message (and a second one for which any message/signature could be taken, e.g. previously known valid one) v2.x is unaffected as it verifies input to be an actual `Uint8Array` instance Such a message can be constructed for any already known message/signature pair, meaning that the attack needs only a single malicious message being signed for a full key extraction While signing unverified attacker-controlled messages would be problematic itself (and exploitation of this needs such a scenario), signing a single message still should not leak the private key Also, message validation could have the same bug (out of scope for this report, but could be possible in some situations), which makes this attack more likely when used in a chain https://github.com/bitcoinjs/tiny-secp256k1/pull/140 is a subtle fix for this ### PoC This code deliberately doesn't provide `funnyBuffer` and `extractTiny` for now, could be updated later ```js import secp256k1 from 'tiny-secp256k1' import crypto from 'crypto' const key = crypto.randomBytes(32) const msg0 = crypto.randomBytes(32) const sig0 = secp256k1.sign(msg0, key).toString('hex') const msg1 = funnyBuffer(msg0) const sig1 = secp256k1.sign(msg1, key).toString('hex') const restored = extractTiny(msg0, sig0, sig1) console.log('Guesses:', JSON.stringify(restored, undefined, 2)) const recheck = (k) => secp256k1.sign(msg0, Buffer.from(k, 'hex')).toString('hex') === sig0 console.log('Rechecked:', JSON.stringify(restored.filter(recheck))) console.log('Actual key', key.toString('hex')) ``` Output: ```console Guesses: [ "8f351953047e6b149e0595547e7d10a8a1edc61bd519b5b2514202a495e434ed", "ebc81e1632a1b3255589ba84364949a0a6fd0229444519765570706d394671dd" ] Rechecked: ["ebc81e1632a1b3255589ba84364949a0a6fd0229444519765570706d394671dd"] Actual key ebc81e1632a1b3255589ba84364949a0a6fd0229444519765570706d394671dd ``` ### Impact Full private key extraction when signing a single malicious message (that passes `JSON.stringify`/`JSON.parse` and can come from network)

如何修補 CVE-2024-49364

要修補 CVE-2024-49364,請將受影響套件升級到下列已修補版本。

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