Take a look at https://github.com/code-423n4/2024-03-zksync/blob/4f0ba34f34a864c354c7e8c47643ed8f4a250e13/code/system-contracts/contracts/Compressor.sol#L44-L70
The publishCompressedBytecode() function has been updated, and here is the new implementation https://github.com/code-423n4/2024-03-zksync/blob/4f0ba34f34a864c354c7e8c47643ed8f4a250e13/code/system-contracts/contracts/Compressor.sol#L44-L70, in comparison to the previous implementation, it no longer enforces multiple checks, i.e the dictionary.length % 8 = 0 and the check where the dictionarys length < 2** 16 this is done so that protocol can correctly enforce more that the reason why a call to this function fails would be due to gas from the bootloader, but there is a new check that faults this logic , i.e require(dictionary.length / 8 <= encodedData.length / 2), issue with this is that this check does not allow the bootloader to correctly enforce that calls to this functiion would mostly fail due to the gas provided not being enough and might still cause the attempt to forcefully revert https://github.com/code-423n4/2024-03-zksync/blob/4f0ba34f34a864c354c7e8c47643ed8f4a250e13/code/system-contracts/bootloader/bootloader.yul#L1740-L1745 i.e an operator passing in a data that does not always fall as correct within the checks, for example say the new check of dictionary.length / 8 <= encodedData.length / 2 is false, would lead to the sendCompressedBytecode() in the bootloader near calling and burning all the gas.
Having it in mind that the sendCompressedBytecode() function is called by the bootloader whenever there is a need for the L2 transaction to use packed bytecode as seen here https://github.com/code-423n4/2024-03-zksync/blob/4f0ba34f34a864c354c7e8c47643ed8f4a250e13/code/system-contracts/bootloader/bootloader.yul#L1506 , this then gives the operator the opportunity of burning all of the users provided gas of any L2 transaction that needs packed/published bytecodes potentially doing it constantly if the operator is malicious since all they need to do is tamper with the data they pass to the bootloader to ensure the compression always ends up malformed by ignoring the new dictionary.length/8 check and then all users attempt just burn their gas.
Since this enforcement dictionary.length / 8 <= encodedData.length / 2 still needs to be placed so as not to allow operator pass in an excessive length, then the near calling should be scrapped from the bootloader when an attempt to sendCompressedBytecode() is made, i.e if the compression is malformed the attempt should instead revert with reason rather than burning all the gas.
Additional Notes
Now we assume the above snippet makes this issue somewhat subjective as we could argue it makes it stand on the lines of being OOS, If all parties think otherwise then this should be upgraded.
