Submitted by bart1e, also found by KingNFT and nmirchev8
https://github.com/code-423n4/2023-12-revolutionprotocol/blob/d42cc62b873a1b2b44f57310f9d4bbfdd875e8d6/packages/revolution/src/AuctionHouse.sol#L370-L371 
https://github.com/code-423n4/2023-12-revolutionprotocol/blob/d42cc62b873a1b2b44f57310f9d4bbfdd875e8d6/packages/revolution/src/AuctionHouse.sol#L385 
https://github.com/code-423n4/2023-12-revolutionprotocol/blob/d42cc62b873a1b2b44f57310f9d4bbfdd875e8d6/packages/revolution/src/CultureIndex.sol#L209-L238 
https://github.com/code-423n4/2023-12-revolutionprotocol/blob/d42cc62b873a1b2b44f57310f9d4bbfdd875e8d6/packages/revolution/src/AuctionHouse.sol#L313 
https://github.com/code-423n4/2023-12-revolutionprotocol/blob/d42cc62b873a1b2b44f57310f9d4bbfdd875e8d6/packages/revolution/src/VerbsToken.sol#L178 
https://github.com/code-423n4/2023-12-revolutionprotocol/blob/d42cc62b873a1b2b44f57310f9d4bbfdd875e8d6/packages/revolution/src/VerbsToken.sol#L282 
https://github.com/code-423n4/2023-12-revolutionprotocol/blob/d42cc62b873a1b2b44f57310f9d4bbfdd875e8d6/packages/revolution/src/VerbsToken.sol#L296-L308
Note: there is another bug (calling verbs.getArtPieceById in a loop in _settleAuction), but this issue focuses on a different attack vector for creating DoS attack, so in this submission, I assume that the bug is fixed (that is, verbs.getArtPieceById is not called in a loop, but cached before it).
This submission shows two implications of the same bug - not limiting length of pieces of art in CultureIndex::createPiece:
CultureIndex::createPiece allows any user to create art pieces. The only validation regarding art piece size performed there is the validation in validateMediaType which only ensures that relevant field in art piece is non-zero.
If an art piece wins voting, its data is then fetched several times (3 - see  note at the beginning of this submission) when verbs.getArtPieceById is called.
If malicious creator creates some nice art piece (for instance of type IMAGE) and hides a very long string in another, irrelevant field (such as ArtPieceMetadata.text) and his piece wins the voting, it will cost a lot of gas to fetch its data both in _settleAuction and _createAuction.
The following implications may occur:
Both exploits require a malicious artwork to win the voting, however, as I have mentioned before, the attacker can hide a very long string in an unrelated field of ArtPieceMetadata structure, so that users may not even notice this and will only pay attention for the image contained in that artwork.
Alternatively, attacker can buy some NontransferableERC20Votes at the beginning and win the voting by himself, before quorum becomes too big.
The impact is severe, but the attack is also costly for the attacker, and under normal circumstances, I would submit the issue as Medium. However, the exploit presented in this submission breaks two invariants that, according to the Sponsor  should NEVER EVER be broken:
The test Im showing will simulate a scenario when a malicious user creates a piece of art containing very long data, that piece wins voting and is then sold.
I assume that the attacker doesnt perform any additional exploits and the bug that I mentioned at the very beginning of this submission is fixed. Moreover, I assume that the attacker specifies only one creator account (if he specified more, he could cause DoS with a less cost - as I have shown in another submission, just by specifying malicious creators he can cause _settleAuction to consume additional ~20 000 000 of gas) as I wanted to measure only the impact of a heavy NFT on the gas cost.
The exploit requires a very long string to be passed - for the exploit to be the most destructive, the string would have to be ~1.3MB long (this will achieve 30 000 000 for the attacker and ~22 000 000 for _settleAuction. The string was not explicitly put in the PoC in order to keep this submission smaller - in order to test it, please add a very long string of \x00s in the place tagged with <- put here a very long string [...]. It is necessary for the string to only contain \x00s since it will significantly reduce cost for the attacker (as sreset, that cost 2900 gas will be used instead of sset, which costs 20 000).
The test will output 3 important values:
Please put the following test into AuctionSettling.t.sol and run it. Please remember to add a very long string of \x00s in the relevant place:
VS Code
Limit the length of all fields in ArtPieceMetadata.
0xTheC0der (Judge) decreased severity to Medium and commented:
