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Phoenix-Protocol-Group / phoenix-contracts

Source code of the smart contracts of the Phoenix DeFi hub DEX protocol
GNU General Public License v3.0
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Fix 0 amount bug in spend_allowance #272

Closed brson closed 5 months ago

brson commented 5 months ago

This fixes a low severity bug in a token contract in this repo.

This repo contains code copied from the Soroban example token, code which recieved a fix in the upstream repo that has not been applied here.

The fix in question, from December, is in this commit:

https://github.com/stellar/soroban-examples/commit/c7947120dc3ef92345d6e019737065d916cfae9d#diff-02d9e91ec617d641664acc20ed164964099f2b96a099109d42cdbb80d44087aeR56

From reading, I think the main consequence of this bug is that a previously-unauthorized spender calling transfer_from can write a 0 to the temporary storage for their own allowance; though it also seems to allow unintended behavior like allowing authorized spenders to extend the ttl of the allowance without transfering.

As far as I know this bug does not have a security impact.

gangov commented 5 months ago

thank you @brson we will also update the token contract as per latest soroban example

gangov commented 5 months ago

merged, thank you @brson