CVE-2021-3748

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Source
https://cve.org/CVERecord?id=CVE-2021-3748
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-3748.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2021-3748
Downstream
Related
Published
2022-03-23T20:15:09.893Z
Modified
2026-05-30T22:00:27.662370Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H CVSS Calculator
Summary
[none]
Details

A use-after-free vulnerability was found in the virtio-net device of QEMU. It could occur when the descriptor's address belongs to the non direct access region, due to num_buffers being set after the virtqueue elem has been unmapped. A malicious guest could use this flaw to crash QEMU, resulting in a denial of service condition, or potentially execute code on the host with the privileges of the QEMU process.

Database specific 
{
    "unresolved_ranges": [
        {
            "vendor_product": "canonical:ubuntu_linux",
            "extracted_events": [
                {
                    "last_affected": "18.04"
                },
                {
                    "last_affected": "20.04"
                },
                {
                    "last_affected": "21.10"
                }
            ],
            "cpes": [
                "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
                "cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*",
                "cpe:2.3:o:canonical:ubuntu_linux:21.10:*:*:*:*:*:*:*"
            ],
            "source": "CPE_STRING"
        },
        {
            "vendor_product": "debian:debian_linux",
            "extracted_events": [
                {
                    "last_affected": "9.0"
                },
                {
                    "last_affected": "10.0"
                }
            ],
            "cpes": [
                "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
                "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*"
            ],
            "source": "CPE_STRING"
        },
        {
            "vendor_product": "fedoraproject:fedora",
            "extracted_events": [
                {
                    "last_affected": "34"
                }
            ],
            "cpes": [
                "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*"
            ],
            "source": "CPE_STRING"
        },
        {
            "vendor_product": "redhat:enterprise_linux",
            "extracted_events": [
                {
                    "last_affected": "8.0"
                }
            ],
            "cpes": [
                "cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:advanced_virtualization:*:*:*"
            ],
            "source": "CPE_STRING"
        },
        {
            "vendor_product": "redhat:enterprise_linux_advanced_virtualization_eus",
            "extracted_events": [
                {
                    "last_affected": "8.4"
                }
            ],
            "cpes": [
                "cpe:2.3:o:redhat:enterprise_linux_advanced_virtualization_eus:8.4:*:*:*:*:*:*:*"
            ],
            "source": "CPE_STRING"
        }
    ]
}
References

Affected packages

Git / github.com/qemu/qemu

Affected ranges

Type
GIT
Repo
https://github.com/qemu/qemu
Events
Introduced
25c4fde17775821182a76fb8ea2ba2223c5729b9
Fixed
44f28df24767cf9dca1ddc9b23157737c4cbb645
Fixed
bedd7e93d01961fcb16a97ae45d93acf357e11f6
Database specific 
{
    "extracted_events": [
        {
            "introduced": "0.10.0"
        },
        {
            "fixed": "6.2.0"
        }
    ],
    "cpe": "cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*",
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ]
}

Database specific

vanir_signatures_modified 
"2026-05-30T22:00:27Z"
vanir_signatures 
[
    {
        "digest": {
            "function_hash": "14770436477810317024841570451115134811",
            "length": 2573.0
        },
        "signature_version": "v1",
        "id": "CVE-2021-3748-63a59022",
        "signature_type": "Function",
        "deprecated": false,
        "target": {
            "file": "hw/net/virtio-net.c",
            "function": "virtio_net_receive_rcu"
        },
        "source": "https://github.com/qemu/qemu/commit/bedd7e93d01961fcb16a97ae45d93acf357e11f6"
    },
    {
        "digest": {
            "line_hashes": [
                "139153011538441137443425885686769242333",
                "19540242830036793152453911828632731321",
                "261971490103105366185518487713065779809",
                "274886746361350886814583306928039415769",
                "117959129944310761007430404673458701437",
                "5575847093833653024836064788740198304",
                "164237186261067155017967658108932275749",
                "41568830874794595423836708667899720764",
                "204979634018619945530189025481137025000",
                "200236562904088385766774625108108467906",
                "81898909521356078802753323202918312736",
                "276622600102277512342777352275962185101",
                "17686686804455707955864788085310989909",
                "170904657820958641358685323667703360232",
                "20732383499291189554247390592397864623",
                "104773052961933199236430616329051629652",
                "30148309516638926374883201050847486195",
                "263405443713322288624440308518443648446",
                "43538856978998950359608723105896316473",
                "135835704044671834425133687155795544491",
                "53527990305242486942412336048341160685",
                "298719444517055338988398675801988708732",
                "162604734227819747815593254388199626104",
                "202154863577782391529005710899301295034",
                "102630445816527384348936569443744793486",
                "107375714520255535024167627018508704968",
                "337770536592677363347602484056375594828",
                "329754777237505547929585834740495934718",
                "309636159462361027173374396889853120124",
                "172880516596470903830738622624501085703",
                "112643539357749891484797476986660340522",
                "259192748648542531221030014246801045362"
            ],
            "threshold": 0.9
        },
        "signature_version": "v1",
        "id": "CVE-2021-3748-b289847e",
        "signature_type": "Line",
        "deprecated": false,
        "target": {
            "file": "hw/net/virtio-net.c"
        },
        "source": "https://github.com/qemu/qemu/commit/bedd7e93d01961fcb16a97ae45d93acf357e11f6"
    }
]
source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-3748.json"

Git / gitlab.com/qemu-project/qemu

Affected ranges

Type
GIT
Repo
https://gitlab.com/qemu-project/qemu
Events
Introduced
25c4fde17775821182a76fb8ea2ba2223c5729b9
Fixed
44f28df24767cf9dca1ddc9b23157737c4cbb645
Database specific 
{
    "extracted_events": [
        {
            "introduced": "0.10.0"
        },
        {
            "fixed": "6.2.0"
        }
    ],
    "cpe": "cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*",
    "source": "CPE_RANGE"
}

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-3748.json"