CVE-2018-18920

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    CVE-2018-18920

    Published: 12 Nov 2018Last Modified: 8 Jul 2026

    Summary:

    Details: Py-EVM v0.2.0-alpha.33 allows attackers to make a vm.execute_bytecode call that triggers computation._stack.values with '"stack": [100, 100, 0]' where b'\x' was expected, resulting in an execution failure because of an invalid opcode. This is reportedly related to "smart contracts can be executed indefinitely without gas being paid."

    References: https://twitter.com/AlexanderFisher/status/1060923428641878019, https://twitter.com/NettaLab/status/1060889400102383617, https://www.reddit.com/r/ethereum/comments/9vkk2g/netta_labs_claim_to_have_found_a_vulnerability_in/e9d3wyx/, https://github.com/ethereum/py-evm/issues/1448

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- a97dee05dba25cd743e5fc43c03add4dc5efd11c
    Fixed -None

    Affected versions

    0.2.0-alpha\.33

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High