{
  "threat_severity" : "Moderate",
  "public_date" : "2023-05-22T06:30:00Z",
  "bugzilla" : {
    "description" : "kernel: netfilter: use-after-free in the packet processing context",
    "id" : "2212140",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2212140"
  },
  "cvss3" : {
    "cvss3_base_score" : "6.6",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-416",
  "details" : [ "An issue was discovered in netfilter in the Linux kernel before 5.10. There can be a use-after-free in the packet processing context, because the per-CPU sequence count is mishandled during concurrent iptables rules replacement. This could be exploited with the CAP_NET_ADMIN capability in an unprivileged namespace. NOTE: cc00bca was reverted in 5.12.", "A use-after-free flaw was found in the packet processing context in net/netfilter/x_tables.c in netfilter in the Linux Kernel. This issue occurs when the per-CPU sequence count is mishandled during concurrent iptables rules replacement and can be exploited with the CAP_NET_ADMIN capability in an unprivileged namespace." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2021-05-18T00:00:00Z",
    "advisory" : "RHSA-2021:1739",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8::nfv",
    "package" : "kernel-rt-0:4.18.0-305.rt7.72.el8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2021-05-18T00:00:00Z",
    "advisory" : "RHSA-2021:1578",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-305.el8"
  } ],
  "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" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2020-36694\nhttps://nvd.nist.gov/vuln/detail/CVE-2020-36694\nhttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cc00bcaa589914096edef7fb87ca5cee4a166b5c" ],
  "name" : "CVE-2020-36694",
  "mitigation" : {
    "value" : "In order to trigger the issue, it requires the ability to create user/net namespaces.\nOn non-containerized deployments of Red Hat Enterprise Linux 8, you can disable user namespaces by setting user.max_user_namespaces to 0:\n# echo \"user.max_user_namespaces=0\" > /etc/sysctl.d/userns.conf\n# sysctl -p /etc/sysctl.d/userns.conf\nOn containerized deployments such as Red Hat OpenShift Container Platform, do not use this mitigation as the functionality is needed to be enabled.",
    "lang" : "en:us"
  },
  "csaw" : false
}