Submitted by Q7, also found by aldarion, Nikki, prapandey031, SBSecurity, DadeKuma, nnez, Silvermist, oakcobalt, shaflow2, ABAIKUNANBAEV, nslavchev, rare_one, OMEN, Testerbot, wasm_it, and devival
The current implementation does not perform a check for lower < upper during mint_position, while many other functions assume lower < upper. This discrepancy allows malicious actors to exploit inconsistencies in handling undefined behavior in other parts of the code for their benefit.
While the attacker cannot directly profit by closing the position, these positions affect fee calculations. For example, in the provided PoC, the attacker can create a large number of empty positions within their liquidity range to collect significant fees from swapping users, inflating what would normally be a fee of 6 to 1605.
Add assert_or!(lower < upper, Error::InvalidTick) check.
Invalid Validation
af-afk (Superposition) confirmed via duplicate issue #59 
0xsomeone (judge) commented:
