Charles Cooper

19 exploits Active since Apr 2022
CVE-2024-32481 WRITEUP MEDIUM WRITEUP
vyper 0.3.8-0.4.0b1 - Denial of Service via Incorrect Signed Integer Comparison in Range Loop
Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. Starting in version 0.3.8 and prior to version 0.4.0b1, when looping over a `range` of the form `range(start, start + N)`, if `start` is negative, the execution will always revert. This issue is caused by an incorrect assertion inserted by the code generation of the range `stmt.parse_For_range()`. The issue arises when `start` is signed, instead of using `sle`, `le` is used and `start` is interpreted as an unsigned integer for the comparison. If it is a negative number, its 255th bit is set to `1` and is hence interpreted as a very large unsigned integer making the assertion always fail. Any contract having a `range(start, start + N)` where `start` is a signed integer with the possibility for `start` to be negative is affected. If a call goes through the loop while supplying a negative `start` the execution will revert. Version 0.4.0b1 fixes the issue.
CVSS 5.3
CVE-2024-32481 WRITEUP MEDIUM WRITEUP
vyper 0.3.8-0.4.0b1 - Denial of Service via Incorrect Signed Integer Comparison in Range Loop
Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. Starting in version 0.3.8 and prior to version 0.4.0b1, when looping over a `range` of the form `range(start, start + N)`, if `start` is negative, the execution will always revert. This issue is caused by an incorrect assertion inserted by the code generation of the range `stmt.parse_For_range()`. The issue arises when `start` is signed, instead of using `sle`, `le` is used and `start` is interpreted as an unsigned integer for the comparison. If it is a negative number, its 255th bit is set to `1` and is hence interpreted as a very large unsigned integer making the assertion always fail. Any contract having a `range(start, start + N)` where `start` is a signed integer with the possibility for `start` to be negative is affected. If a call goes through the loop while supplying a negative `start` the execution will revert. Version 0.4.0b1 fixes the issue.
CVSS 5.3
CVE-2022-24787 WRITEUP HIGH WRITEUP
vyper < 0.3.1 - Incorrect Bytestring Comparison
Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine. In version 0.3.1 and prior, bytestrings can have dirty bytes in them, resulting in the word-for-word comparisons giving incorrect results. Even without dirty nonzero bytes, two bytestrings can compare to equal if one ends with `"\x00"` because there is no comparison of the length. A patch is available and expected to be part of the 0.3.2 release. There are currently no known workarounds.
CVSS 7.5
CVE-2022-24788 WRITEUP HIGH WRITEUP
vyper < 0.3.2 - Buffer Overrun via JSON Interface Function Import
Vyper is a pythonic Smart Contract Language for the ethereum virtual machine. Versions of vyper prior to 0.3.2 suffer from a potential buffer overrun. Importing a function from a JSON interface which returns `bytes` generates bytecode which does not clamp bytes length, potentially resulting in a buffer overrun. Users are advised to upgrade. There are no known workarounds for this issue.
CVSS 7.1
CVE-2022-24845 WRITEUP HIGH WRITEUP
vyperlang/vyper < 0.3.2 - Integer Overflow via Unvalidated int128 Return
Vyper is a pythonic Smart Contract Language for the ethereum virtual machine. In affected versions, the return of `<iface>.returns_int128()` is not validated to fall within the bounds of `int128`. This issue can result in a misinterpretation of the integer value and lead to incorrect behavior. As of v0.3.0, `<iface>.returns_int128()` is validated in simple expressions, but not complex expressions. Users are advised to upgrade. There is no known workaround for this issue.
CVSS 8.8
CVE-2022-29255 WRITEUP HIGH WRITEUP
vyper < 0.3.4 - Always-Incorrect Control Flow Implementation in External Contract Calls
Vyper is a Pythonic Smart Contract Language for the ethereum virtual machine. In versions prior to 0.3.4 when a calling an external contract with no return value, the contract address (including side effects) could be evaluated twice. This may result in incorrect outcomes for contracts. This issue has been addressed in v0.3.4.
CVSS 8.2
CVE-2023-30629 WRITEUP HIGH WRITEUP
vyper 0.3.1-0.3.7 - Always-Incorrect Control Flow Implementation in raw_call
Vyper is a Pythonic Smart Contract Language for the ethereum virtual machine. In versions 0.3.1 through 0.3.7, the Vyper compiler generates the wrong bytecode. Any contract that uses the `raw_call` with `revert_on_failure=False` and `max_outsize=0` receives the wrong response from `raw_call`. Depending on the memory garbage, the result can be either `True` or `False`. A patch is available and, as of time of publication, anticipated to be part of Vyper 0.3.8. As a workaround, one may always put `max_outsize>0`.
CVSS 7.5
CVE-2023-30837 WRITEUP HIGH WRITEUP
vyper < 0.3.8 - Memory Allocation with Excessive Size Value
Vyper is a pythonic smart contract language for the EVM. The storage allocator does not guard against allocation overflows in versions prior to 0.3.8. An attacker can overwrite the owner variable. This issue was fixed in version 0.3.8.
CVSS 7.5
CVE-2023-31146 WRITEUP HIGH WRITEUP
vyper < 0.3.8 - Out-of-bounds Write via Dynamic Array Assignment
Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, during codegen, the length word of a dynarray is written before the data, which can result in out-of-bounds array access in the case where the dynarray is on both the lhs and rhs of an assignment. The issue can cause data corruption across call frames. The expected behavior is to revert due to out-of-bounds array access. Version 0.3.8 contains a patch for this issue.
CVSS 7.5
CVE-2023-32058 WRITEUP HIGH WRITEUP
vyper < 0.3.8 - Integer Overflow in Loop Iterator Assignment
Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, due to missing overflow check for loop variables, by assigning the iterator of a loop to a variable, it is possible to overflow the type of the latter. The issue seems to happen only in loops of type `for i in range(a, a + N)` as in loops of type `for i in range(start, stop)` and `for i in range(stop)`, the compiler is able to raise a `TypeMismatch` when trying to overflow the variable. The problem has been patched in version 0.3.8.
CVSS 7.5
CVE-2023-32059 WRITEUP HIGH WRITEUP
vyper < 0.3.8 - Incorrect Internal Call Argument Ordering
Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, internal calls with default arguments are compiled incorrectly. Depending on the number of arguments provided in the call, the defaults are added not right-to-left, but left-to-right. If the types are incompatible, typechecking is bypassed. The ability to pass kwargs to internal functions is an undocumented feature that is not well known about. The issue is patched in version 0.3.8.
CVSS 7.5
CVE-2023-32675 WRITEUP LOW WRITEUP
vyperlang/vyper < 0.3.8 - Incorrect Fund Transfer via Nonpayable Default Function
Vyper is a pythonic Smart Contract Language for the ethereum virtual machine. In contracts with more than one regular nonpayable function, it is possible to send funds to the default function, even if the default function is marked `nonpayable`. This applies to contracts compiled with vyper versions prior to 0.3.8. This issue was fixed by the removal of the global `calldatasize` check in commit `02339dfda`. Users are advised to upgrade to version 0.3.8. Users unable to upgrade should avoid use of nonpayable default functions.
CVSS 3.7
CVE-2023-37902 WRITEUP MEDIUM WRITEUP
vyper < 0.3.10 - Unchecked Return Value in ecrecover Precompile
Vyper is a Pythonic programming language that targets the Ethereum Virtual Machine (EVM). Prior to version 0.3.10, the ecrecover precompile does not fill the output buffer if the signature does not verify. However, the ecrecover builtin will still return whatever is at memory location 0. This means that the if the compiler has been convinced to write to the 0 memory location with specially crafted data (generally, this can happen with a hashmap access or immutable read) just before the ecrecover, a signature check might pass on an invalid signature. Version 0.3.10 contains a patch for this issue.
CVSS 5.3
CVE-2023-42441 WRITEUP MEDIUM WRITEUP
vyper 0.2.9-0.3.9 - Improper Locking in Nonreentrant Decorator
Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). Starting in version 0.2.9 and prior to version 0.3.10, locks of the type `@nonreentrant("")` or `@nonreentrant('')` do not produce reentrancy checks at runtime. This issue is fixed in version 0.3.10. As a workaround, ensure the lock name is a non-empty string.
CVSS 5.3
CVE-2023-46247 WRITEUP HIGH WRITEUP
vyper < 0.3.8 - Incorrect Storage Slot Calculation via Floating-Point Rounding Error
Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). Contracts containing large arrays might underallocate the number of slots they need by 1. Prior to v0.3.8, the calculation to determine how many slots a storage variable needed used `math.ceil(type_.size_in_bytes / 32)`. The intermediate floating point step can produce a rounding error if there are enough bits set in the IEEE-754 mantissa. Roughly speaking, if `type_.size_in_bytes` is large (> 2**46), and slightly less than a power of 2, the calculation can overestimate how many slots are needed by 1. If `type_.size_in_bytes` is slightly more than a power of 2, the calculation can underestimate how many slots are needed by 1. This issue is patched in version 0.3.8.
CVSS 7.5
CVE-2024-22419 WRITEUP HIGH WRITEUP
vyper < 0.3.10 and >=0.3.0 <0.4.0 - Buffer Overflow in concat Built-in
Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine. The `concat` built-in can write over the bounds of the memory buffer that was allocated for it and thus overwrite existing valid data. The root cause is that the `build_IR` for `concat` doesn't properly adhere to the API of copy functions (for `>=0.3.2` the `copy_bytes` function). A contract search was performed and no vulnerable contracts were found in production. The buffer overflow can result in the change of semantics of the contract. The overflow is length-dependent and thus it might go unnoticed during contract testing. However, certainly not all usages of concat will result in overwritten valid data as we require it to be in an internal function and close to the return statement where other memory allocations don't occur. This issue has been addressed in 0.4.0.
CVSS 7.3
CVE-2024-24564 WRITEUP LOW WRITEUP
vyper < 0.4.0 - Out-of-bounds Read via extract32 Function
Vyper is a pythonic Smart Contract Language for the ethereum virtual machine. When using the built-in `extract32(b, start)`, if the `start` index provided has for side effect to update `b`, the byte array to extract `32` bytes from, it could be that some dirty memory is read and returned by `extract32`. This vulnerability is fixed in 0.4.0.
CVSS 3.7
CVE-2024-32648 WRITEUP MEDIUM WRITEUP
vyperlang/vyper < 0.3.0 - Improper Locking in Default Functions
Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. Prior to version 0.3.0, default functions don't respect nonreentrancy keys and the lock isn't emitted. No vulnerable production contracts were found. Additionally, using a lock on a `default` function is a very sparsely used pattern. As such, the impact is low. Version 0.3.0 contains a patch for the issue.
CVSS 5.3
CVE-2025-21607 WRITEUP HIGH WRITEUP
vyperlang/vyper < 0.4.1 - Always-Incorrect Control Flow Implementation in EcRecover and Identity Precompiles
Vyper is a Pythonic Smart Contract Language for the EVM. When the Vyper Compiler uses the precompiles EcRecover (0x1) and Identity (0x4), the success flag of the call is not checked. As a consequence an attacker can provide a specific amount of gas to make these calls fail but let the overall execution continue. Then the execution result can be incorrect. Based on EVM's rules, after the failed precompile the remaining code has only 1/64 of the pre-call-gas left (as 63/64 were forwarded and spent). Hence, only fairly simple executions can follow the failed precompile calls. Therefore, we found no significantly impacted real-world contracts. None the less an advisory has been made out of an abundance of caution. This issue is fixed in 0.4.1.
CVSS 7.5