{
    "CVE_data_meta": {
        "ASSIGNER": "security-advisories@github.com",
        "ID": "CVE-2020-26241",
        "STATE": "PUBLIC",
        "TITLE": "Shallow copy bug in geth"
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "product": {
                        "product_data": [
                            {
                                "product_name": "go-ethereum",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_value": ">= 1.9.7, < 1.9.17"
                                        }
                                    ]
                                }
                            }
                        ]
                    },
                    "vendor_name": "ethereum"
                }
            ]
        }
    },
    "data_format": "MITRE",
    "data_type": "CVE",
    "data_version": "4.0",
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "Go Ethereum, or \"Geth\", is the official Golang implementation of the Ethereum protocol. This is a Consensus vulnerability in Geth before version 1.9.17 which can be used to cause a chain-split where vulnerable nodes reject the canonical chain. Geth's pre-compiled dataCopy (at 0x00...04) contract did a shallow copy on invocation. An attacker could deploy a contract that writes X to an EVM memory region R, then calls 0x00..04 with R as an argument, then overwrites R to Y, and finally invokes the RETURNDATACOPY opcode. When this contract is invoked, a consensus-compliant node would push X on the EVM stack, whereas Geth would push Y. This is fixed in version 1.9.17."
            }
        ]
    },
    "impact": {
        "cvss": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
            "version": "3.1"
        }
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "CWE-682: Incorrect Calculation"
                    }
                ]
            }
        ]
    },
    "references": {
        "reference_data": [
            {
                "name": "https://blog.ethereum.org/2020/11/12/geth_security_release/",
                "refsource": "MISC",
                "url": "https://blog.ethereum.org/2020/11/12/geth_security_release/"
            },
            {
                "name": "https://github.com/ethereum/go-ethereum/security/advisories/GHSA-69v6-xc2j-r2jf",
                "refsource": "CONFIRM",
                "url": "https://github.com/ethereum/go-ethereum/security/advisories/GHSA-69v6-xc2j-r2jf"
            }
        ]
    },
    "source": {
        "advisory": "GHSA-69v6-xc2j-r2jf",
        "discovery": "UNKNOWN"
    }
}