{
    "CVE_data_meta": {
        "ASSIGNER": "security@ubuntu.com",
        "DATE_PUBLIC": "2021-05-11 17:00:00 +0000",
        "ID": "CVE-2021-3491",
        "STATE": "PUBLIC",
        "TITLE": "Linux kernel io_uring PROVIDE_BUFFERS MAX_RW_COUNT  bypass"
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Linux kernel",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "trunk",
                                            "version_value": "v5.13-rc4"
                                        },
                                        {
                                            "version_affected": "<",
                                            "version_name": "linux-5.12.y",
                                            "version_value": "v5.12.4"
                                        },
                                        {
                                            "version_affected": "<",
                                            "version_name": "linux-5.11.y",
                                            "version_value": "v5.11.21"
                                        },
                                        {
                                            "version_affected": "<",
                                            "version_name": "linux-5.10.y",
                                            "version_value": "v5.10.37"
                                        },
                                        {
                                            "version_affected": ">=",
                                            "version_name": "5.7",
                                            "version_value": "v5.7-rc1"
                                        }
                                    ]
                                }
                            }
                        ]
                    },
                    "vendor_name": "Linux"
                }
            ]
        }
    },
    "credit": [
        {
            "lang": "eng",
            "value": "Billy Jheng Bing-Jhong (@st424204) of STAR Labs working with Trend Micro's Zero Day Initiative"
        }
    ],
    "data_format": "MITRE",
    "data_type": "CVE",
    "data_version": "4.0",
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "The io_uring subsystem in the Linux kernel allowed the MAX_RW_COUNT limit to be bypassed in the PROVIDE_BUFFERS operation, which led to negative values being usedin mem_rw when reading /proc/<PID>/mem. This could be used to create a heap overflow leading to arbitrary code execution in the kernel. It was addressed via commit d1f82808877b (\"io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers\") (v5.13-rc1) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced in ddf0322db79c (\"io_uring: add IORING_OP_PROVIDE_BUFFERS\") (v5.7-rc1)."
            }
        ]
    },
    "generator": {
        "engine": "Vulnogram 0.0.9"
    },
    "impact": {
        "cvss": {
            "attackComplexity": "HIGH",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
        }
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "CWE-131 Incorrect Calculation of Buffer Size"
                    }
                ]
            }
        ]
    },
    "references": {
        "reference_data": [
            {
                "name": "https://ubuntu.com/security/notices/USN-4950-1",
                "refsource": "UBUNTU",
                "url": "https://ubuntu.com/security/notices/USN-4950-1"
            },
            {
                "name": "https://ubuntu.com/security/notices/USN-4949-1",
                "refsource": "UBUNTU",
                "url": "https://ubuntu.com/security/notices/USN-4949-1"
            },
            {
                "name": "[oss-security] CVE-2021-3491 - Linux kernel io_uring PROVIDE_BUFFERS MAX_RW_COUNT  bypass",
                "refsource": "MLIST",
                "url": "https://www.openwall.com/lists/oss-security/2021/05/11/13"
            },
            {
                "name": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d1f82808877bb10d3deee7cf3374a4eb3fb582db",
                "refsource": "MISC",
                "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d1f82808877bb10d3deee7cf3374a4eb3fb582db"
            },
            {
                "name": "https://www.zerodayinitiative.com/advisories/ZDI-21-589/",
                "refsource": "MISC",
                "url": "https://www.zerodayinitiative.com/advisories/ZDI-21-589/"
            },
            {
                "refsource": "CONFIRM",
                "name": "https://security.netapp.com/advisory/ntap-20210716-0004/",
                "url": "https://security.netapp.com/advisory/ntap-20210716-0004/"
            }
        ]
    },
    "source": {
        "discovery": "EXTERNAL"
    }
}