{
  "threat_severity" : "Moderate",
  "public_date" : "2023-09-06T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: use after free in nft_immediate_deactivate",
    "id" : "2237752",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2237752"
  },
  "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 netfilter: nf_tables component can be exploited to achieve local privilege escalation.\nOn an error when building a nftables rule, deactivating immediate expressions in nft_immediate_deactivate() can lead unbinding the chain and objects be deactivated but later used.\nWe recommend upgrading past commit 0a771f7b266b02d262900c75f1e175c7fe76fec2.", "A use-after-free flaw was found in the Linux kernel's netfilter: nf_tables component, which can be exploited to achieve local privilege escalation. On an error when building a nftables rule, deactivating immediate expressions in nft_immediate_deactivate() can unbind the chain and objects can be deactivated but used later." ],
  "statement" : "Exploiting this flaw will require CAP_NET_ADMIN access privilege in any user or network namespace and on non-containerized deployments of Red Hat Enterprise Linux, you can disable user namespaces by setting user.max_user_namespaces to 0:\n~~~\necho \"user.max_user_namespaces=0\" > /etc/sysctl.d/userns.conf\nsysctl -p /etc/sysctl.d/userns.conf\n~~~\nOn containerized deployments such as Red Hat OpenShift Container Platform, do not use this mitigation as the functionality is needed to be enabled.",
  "affected_release" : [ {
    "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" : "2024-01-25T00:00:00Z",
    "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 9.2 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"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "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-2023-4015\nhttps://nvd.nist.gov/vuln/detail/CVE-2023-4015\nhttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0a771f7b266b02d262900c75f1e175c7fe76fec2" ],
  "name" : "CVE-2023-4015",
  "mitigation" : {
    "value" : "Mitigation for this issue is to skip loading the affected module \"netfilter\" onto the system till we have a fix available, this can be done by a blacklist mechanism, this will ensure the driver is not loaded at the boot time.\n~~~\nHow do I blacklist a kernel module to prevent it from loading automatically?\nhttps://access.redhat.com/solutions/41278 \n~~~",
    "lang" : "en:us"
  },
  "csaw" : false
}