{
  "threat_severity" : "Important",
  "public_date" : "2023-09-06T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: net/sched: sch_hfsc UAF",
    "id" : "2237757",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2237757"
  },
  "cvss3" : {
    "cvss3_base_score" : "7.8",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-416",
  "details" : [ "A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation.\nIf a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free.\nWe recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.", "A use-after-free flaw was found in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, with the HFSC_FSC flag set, has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free issue." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 7",
    "release_date" : "2024-04-23T00:00:00Z",
    "advisory" : "RHSA-2024:2003",
    "cpe" : "cpe:/a:redhat:rhel_extras_rt:7",
    "package" : "kernel-rt-0:3.10.0-1160.118.1.rt56.1269.el7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "release_date" : "2024-04-23T00:00:00Z",
    "advisory" : "RHSA-2024:1960",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7",
    "package" : "kpatch-patch"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "release_date" : "2024-04-23T00:00:00Z",
    "advisory" : "RHSA-2024:2004",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7",
    "package" : "kernel-0:3.10.0-1160.118.1.el7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7.6 Advanced Update Support(Disable again in 2026 - SPRHEL-7118)",
    "release_date" : "2024-04-10T00:00:00Z",
    "advisory" : "RHSA-2024:1747",
    "cpe" : "cpe:/o:redhat:rhel_aus:7.6",
    "package" : "kernel-0:3.10.0-957.112.1.el7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7.7 Advanced Update Support",
    "release_date" : "2024-04-10T00:00:00Z",
    "advisory" : "RHSA-2024:1746",
    "cpe" : "cpe:/o:redhat:rhel_aus:7.7",
    "package" : "kernel-0:3.10.0-1062.87.1.el7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2024-02-20T00:00:00Z",
    "advisory" : "RHSA-2024:0881",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8::nfv",
    "package" : "kernel-rt-0:4.18.0-513.18.1.rt7.320.el8_9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2024-02-20T00:00:00Z",
    "advisory" : "RHSA-2024:0876",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kpatch-patch"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2024-02-20T00:00:00Z",
    "advisory" : "RHSA-2024:0897",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-513.18.1.el8_9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.2 Advanced Update Support",
    "release_date" : "2024-03-12T00:00:00Z",
    "advisory" : "RHSA-2024:1268",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.2",
    "package" : "kernel-0:4.18.0-193.128.1.el8_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.2 Telecommunications Update Service",
    "release_date" : "2024-03-12T00:00:00Z",
    "advisory" : "RHSA-2024:1269",
    "cpe" : "cpe:/a:redhat:rhel_tus:8.2::nfv",
    "package" : "kernel-rt-0:4.18.0-193.128.1.rt13.179.el8_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.2 Telecommunications Update Service",
    "release_date" : "2024-03-12T00:00:00Z",
    "advisory" : "RHSA-2024:1268",
    "cpe" : "cpe:/o:redhat:rhel_tus:8.2",
    "package" : "kernel-0:4.18.0-193.128.1.el8_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.2 Update Services for SAP Solutions",
    "release_date" : "2024-03-12T00:00:00Z",
    "advisory" : "RHSA-2024:1268",
    "cpe" : "cpe:/o:redhat:rhel_e4s:8.2",
    "package" : "kernel-0:4.18.0-193.128.1.el8_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.2 Update Services for SAP Solutions",
    "release_date" : "2024-03-12T00:00:00Z",
    "advisory" : "RHSA-2024:1278",
    "cpe" : "cpe:/o:redhat:rhel_e4s:8.2",
    "package" : "kpatch-patch"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support",
    "release_date" : "2024-01-30T00:00:00Z",
    "advisory" : "RHSA-2024:0562",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.4",
    "package" : "kernel-0:4.18.0-305.120.1.el8_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Telecommunications Update Service",
    "release_date" : "2024-01-30T00:00:00Z",
    "advisory" : "RHSA-2024:0563",
    "cpe" : "cpe:/a:redhat:rhel_tus:8.4::nfv",
    "package" : "kernel-rt-0:4.18.0-305.120.1.rt7.196.el8_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Telecommunications Update Service",
    "release_date" : "2024-01-30T00:00:00Z",
    "advisory" : "RHSA-2024:0562",
    "cpe" : "cpe:/o:redhat:rhel_tus:8.4",
    "package" : "kernel-0:4.18.0-305.120.1.el8_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions",
    "release_date" : "2024-01-30T00:00:00Z",
    "advisory" : "RHSA-2024:0562",
    "cpe" : "cpe:/o:redhat:rhel_e4s:8.4",
    "package" : "kernel-0:4.18.0-305.120.1.el8_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions",
    "release_date" : "2024-01-30T00:00:00Z",
    "advisory" : "RHSA-2024:0593",
    "cpe" : "cpe:/o:redhat:rhel_e4s:8.4",
    "package" : "kpatch-patch"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Extended Update Support",
    "release_date" : "2024-01-23T00:00:00Z",
    "advisory" : "RHSA-2024:0378",
    "cpe" : "cpe:/o:redhat:rhel_eus:8.6",
    "package" : "kpatch-patch"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Extended Update Support",
    "release_date" : "2024-01-25T00:00:00Z",
    "advisory" : "RHSA-2024:0412",
    "cpe" : "cpe:/o:redhat:rhel_eus:8.6",
    "package" : "kernel-0:4.18.0-372.87.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.8 Extended Update Support",
    "release_date" : "2024-01-30T00:00:00Z",
    "advisory" : "RHSA-2024:0554",
    "cpe" : "cpe:/o:redhat:rhel_eus:8.8",
    "package" : "kpatch-patch"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.8 Extended Update Support",
    "release_date" : "2024-01-30T00:00:00Z",
    "advisory" : "RHSA-2024:0575",
    "cpe" : "cpe:/o:redhat:rhel_eus:8.8",
    "package" : "kernel-0:4.18.0-477.43.1.el8_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2024-01-25T00:00:00Z",
    "advisory" : "RHSA-2024:0461",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-362.18.1.el9_3"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2024-01-23T00:00:00Z",
    "advisory" : "RHSA-2024:0340",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kpatch-patch"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2024-01-25T00:00:00Z",
    "advisory" : "RHSA-2024:0461",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-362.18.1.el9_3"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.0 Extended Update Support",
    "release_date" : "2024-01-25T00:00:00Z",
    "advisory" : "RHSA-2024:0432",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.0",
    "package" : "kernel-0:5.14.0-70.85.1.el9_0"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.0 Extended Update Support",
    "release_date" : "2024-01-25T00:00:00Z",
    "advisory" : "RHSA-2024:0431",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.0::nfv",
    "package" : "kernel-rt-0:5.14.0-70.85.1.rt21.156.el9_0"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.0 Extended Update Support",
    "release_date" : "2024-01-24T00:00:00Z",
    "advisory" : "RHSA-2024:0386",
    "cpe" : "cpe:/o:redhat:rhel_eus:9.0",
    "package" : "kpatch-patch"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Extended Update Support",
    "release_date" : "2024-01-25T00:00:00Z",
    "advisory" : "RHSA-2024:0448",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.2",
    "package" : "kernel-0:5.14.0-284.48.1.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Extended Update Support",
    "release_date" : "2024-01-25T00:00:00Z",
    "advisory" : "RHSA-2024:0439",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.2::nfv",
    "package" : "kernel-rt-0:5.14.0-284.48.1.rt14.333.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Extended Update Support",
    "release_date" : "2024-01-23T00:00:00Z",
    "advisory" : "RHSA-2024:0381",
    "cpe" : "cpe:/o:redhat:rhel_eus:9.2",
    "package" : "kpatch-patch"
  }, {
    "product_name" : "Red Hat Virtualization 4 for Red Hat Enterprise Linux 8",
    "release_date" : "2024-01-25T00:00:00Z",
    "advisory" : "RHSA-2024:0412",
    "cpe" : "cpe:/o:redhat:rhev_hypervisor:4.4::el8",
    "package" : "kernel-0:4.18.0-372.87.1.el8_6"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2023-4623\nhttps://nvd.nist.gov/vuln/detail/CVE-2023-4623\nhttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f" ],
  "name" : "CVE-2023-4623",
  "mitigation" : {
    "value" : "To mitigate this issue, prevent the module sch_hfsc from being loaded by blacklisting the module to prevent it from loading automatically. \n~~~\nhttps://access.redhat.com/solutions/41278 \n~~~",
    "lang" : "en:us"
  },
  "csaw" : false
}