XRP Ledger activates fix for token-minting permission bug

The XRP Ledger activated a fix on Wednesday for a permission bug that could let an account authorized to destroy issued tokens create new ones, according to CoinDesk’s report on the activation. The change, called fixCleanup3_4_0, took effect at 14:52 UTC at ledger 108,112,129. The flaw involved tokens issued on the network, including stablecoins, and did not affect XRP itself.

The bug was in the XRP Ledger’s permission system, which lets one account delegate specific actions to another. A business could, for example, let a payment service destroy tokens when customers redeem them, without authorizing it to issue more. Before the fix, the delegated “PaymentBurn” permission could also allow token creation in certain circumstances.

How does the fix separate burning from minting?

The fix blocks a delegated payment from creating tokens by taking an account’s balance below zero unless the delegate also has permission to mint, according to the XRP Ledger’s amendment documentation. In everyday terms, an account allowed to remove tokens can no longer use that permission alone to make new ones. The correction covers fungible tokens issued on the ledger, including trust line tokens and multi-purpose tokens.

The amendment is one part of a larger package of ledger changes. XRPL’s documentation lists additional corrections for vaults, lending, trading, NFTs, escrow and transaction signing. The token permission fix addresses the specific boundary between destroying an issued token and creating one.

What changed from the previous rules?

Previously, an account with the limited PaymentBurn permission could, in some circumstances, create new issued tokens while making a payment. Under the corrected rule, that payment is rejected unless the account also has PaymentMint permission. The distinction matters for issuers that delegate token redemption to another service but want to keep issuance under separate control.

The amendment required validator support before it could take effect, and an earlier activation attempt was interrupted when support dipped in October, CoinDesk reported. The network then needed two uninterrupted weeks of support above its threshold; the fix went live after that process completed. CoinDesk reported no publicly confirmed cases of the flaw being exploited.

Source material

• CoinDesk’s report on the activation — coindesk.com
• XRP Ledger’s amendment documentation — xrpl.org