GHSA-84c3-j8r2-mcm8: 
JavaScript vulnerability analysis and mitigation

A critical vulnerability was discovered in the @nfid/embed SDK and @dfinity/auth-client library affecting versions >=0.20.0-beta.0 and <1.0.1. The issue involves compromised Ed25519 key generation where the library failed to generate secure random seeds for key pairs, instead using an insecure seed that resulted in a compromised private key (535yc-uxytb-gfk7h-tny7p-vjkoe-i4krp-3qmcl-uqfgr-cpgej-yqtjq-rqe). The vulnerability was disclosed on February 26, 2024, and has been assigned CVE-2024-27084 (GitHub Advisory).

The vulnerability stems from the Ed25519KeyIdentity.generate function in the DFINITY auth client library. While the function includes an optional parameter for providing a 32-byte seed value for secret key generation, a recent update compromised the secure randomness generation when no seed value is provided. The vulnerability has been assigned a CVSS score of 9.1 (Critical), with base metrics indicating network attack vector, low attack complexity, no privileges required, and no user interaction needed. The weakness has been categorized under CWE-321 and CWE-330 (AgentJS Advisory).

The vulnerability exposes users to potential loss of funds on ledgers and unauthorized access to canisters they control. Since the private key is compromised, attackers could gain access to any assets or resources associated with the affected principal on ledgers or lose control over canisters where this principal is the controller (GitHub Advisory).

Users are advised to upgrade to version 1.0.1 of @dfinity/auth-client and @dfinity/identity packages, or @nfid/embed version 0.10.1-alpha.6 or higher. For developers unable to upgrade, temporary workarounds include invoking Ed25519KeyIdentity.generate(null) to force secure random seed generation or passing a securely generated randomness as a seed. Users should check their canister controllers and remove the compromised principal, and transfer any funds from affected wallet accounts to new accounts immediately (AgentJS Advisory).