CVE-2024-26149 – vyper

Package

Manager: pip
Name: vyper
Vulnerable Version: >=0 <0.4.0

Severity

Level: Low

CVSS v3.1: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS v4.0: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

EPSS: 0.0039 pctl0.59265

Details

Vyper's `_abi_decode` vulnerable to Memory Overflow ## Summary If an excessively large value is specified as the starting index for an array in `_abi_decode`, it can cause the read position to overflow. This results in the decoding of values outside the intended array bounds, potentially leading to bugs in contracts that use arrays within `_abi_decode`. The advisory has been assigned low severity, because it is only observable if there is a memory write between two invocations of `abi_decode` on the same input. ## Proof of Concept ```vyper event Pwn: pass @external def f(x: Bytes[32 * 3]): a: Bytes[32] = b"foo" y: Bytes[32 * 3] = x decoded_y1: Bytes[32] = _abi_decode(y, Bytes[32]) a = b"bar" decoded_y2: Bytes[32] = _abi_decode(y, Bytes[32]) if decoded_y1 != decoded_y2: log Pwn() ``` Sending the following calldata results in `Pwn` being emitted. ``` 0xd45754f8 0000000000000000000000000000000000000000000000000000000000000020 0000000000000000000000000000000000000000000000000000000000000060 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffa0 ``` ### Patches Patched in https://github.com/vyperlang/vyper/pull/3925, https://github.com/vyperlang/vyper/pull/4091, https://github.com/vyperlang/vyper/pull/4144, https://github.com/vyperlang/vyper/pull/4060.

Metadata

Created: 2024-02-26T20:11:07Z
Modified: 2025-01-17T15:54:37Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/02/GHSA-9p8r-4xp4-gw5w/GHSA-9p8r-4xp4-gw5w.json
CWE IDs: ["CWE-119", "CWE-120"]
Alternative ID: GHSA-9p8r-4xp4-gw5w
Finding: F316
Auto approve: 1