Solana Quietly Fixes Bug That Could Have Let Attackers Mint and Steal Certain Tokens

The Solana Foundation has disclosed a antecedently chartless vulnerability successful its privacy-focused token strategy that could person allowed attackers to forge fake zero-knowledge proofs, enabling unauthorized minting oregon withdrawals of tokens.

The vulnerability was archetypal reported connected April 16 done Anza’s GitHub information advisory, accompanied by a moving proof-of-concept. Engineers from Solana improvement teams Anza, Firedancer, and Jito verified the bug and began moving connected a hole immediately, per a post-mortem published Saturday,

The contented stemmed from the ZK ElGamal Proof program, which verifies zero-knowledge proofs (ZKPs) utilized successful Solana’s Token-22 confidential transfers. These hold tokens alteration backstage balances and transfers by encrypting amounts and utilizing cryptographic proofs to validate them.

ZKPs are a cryptographic method that lets idiosyncratic beryllium they cognize oregon person entree to something, specified arsenic a password oregon age, without revealing the happening itself.

In crypto applications, these tin beryllium utilized to beryllium a transaction is valid without showing circumstantial amounts oregon addresses (which tin different beryllium utilized by malicious actors to program exploits).

The bug occurred due to the fact that immoderate algebraic components were missing from the hashing process during the Fiat-Shamir translation — a modular method to marque zero-knowledge proofs non-interactive. (Non-interactive means turning a back-and-forth process into a one-time impervious anyone tin verify.)

A blase attacker could forge invalid proofs that the on-chain verifier would inactive accept.

This would person allowed unauthorized actions specified arsenic minting unlimited tokens oregon withdrawing tokens from different accounts.

As such, the vulnerability did not impact modular SPL tokens oregon the main Token-2022 programme logic.

Patches were distributed privately to validator operators opening April 17. A 2nd spot was pushed aboriginal that evening to code a related contented elsewhere successful the codebase.

Both were reviewed by third-party information firms Asymmetric Research, Neodyme, and OtterSec. By April 18, a supermajority of validators had adopted the fix.

There is nary denotation that the bug was exploited, and each funds stay secure, according to the post-mortem.