CVE-2023-30837: Vyper storage allocator overflow
Impact The storage allocator does not guard against allocation overflows. This can result in vulnerabilities like the following: vyper owner: public(address) takeupsomespace: public(uint256[10]) buffer: public(uint256[maxvalue(uint256)])
@external def initialize(): self.owner = msg.sender
@external def foo(idx: uint256, data: uint256): self.buffer[idx] = data Per @toonvanhove, "An attacker can overwrite the owner variable by calling this contract with calldata: 0x04bc52f8 fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff5 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff (spaces inserted for readability) 0x04bc52f8 is the selector for foo(uint256, uint256), and the last argument fff...fff is the new value for the owner variable."
Patches patched in 0bb7203b584e771b23536ba065a6efda457161bb
Workarounds Is there a way for users to fix or remediate the vulnerability without upgrading?
References Are there any links users can visit to find out more?
Other sources
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.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is CVE-2023-30837?
CVE-2023-30837 is a vulnerability in the Vyper smart contract language for the EVM related to the storage allocator not guarding against allocation overflows.
How does CVE-2023-30837 impact the affected software?
CVE-2023-30837 can result in vulnerabilities like buffer overflow, which can be exploited by attackers.
What is the severity of CVE-2023-30837?
CVE-2023-30837 has a severity rating of high.
Which versions of Vyper are affected by CVE-2023-30837?
Vyper versions up to but excluding 0.3.8 are affected by CVE-2023-30837.
How can I mitigate CVE-2023-30837?
To mitigate CVE-2023-30837, make sure to update Vyper to version 0.3.8 or later.