{
  "threat_severity" : "Moderate",
  "public_date" : "2024-05-21T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: mISDN: fix possible use-after-free in HFC_cleanup()",
    "id" : "2282394",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2282394"
  },
  "cvss3" : {
    "cvss3_base_score" : "6.7",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-416",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nmISDN: fix possible use-after-free in HFC_cleanup()\nThis module's remove path calls del_timer(). However, that function\ndoes not wait until the timer handler finishes. This means that the\ntimer handler may still be running after the driver's remove function\nhas finished, which would result in a use-after-free.\nFix by calling del_timer_sync(), which makes sure the timer handler\nhas finished, and unable to re-schedule itself.", "A vulnerability was found in the Linux kernel's mISDN driver. This issue arises during the cleanup process, where a timer handler might still be running after the driver has been removed, which can lead to a use-after-free issue, potentially causing a system crash." ],
  "statement" : "This vulnerability is rated as a moderate severity because it can cause system crash but it requires a specific conditions to be triggered, including the concurrent removal of the driver and active timer operations.",
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2024-07-08T00:00:00Z",
    "advisory" : "RHSA-2024:4352",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8::nfv",
    "package" : "kernel-rt-0:4.18.0-553.8.1.rt7.349.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2024-07-02T00:00:00Z",
    "advisory" : "RHSA-2024:4211",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-553.8.1.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support",
    "release_date" : "2024-08-21T00:00:00Z",
    "advisory" : "RHSA-2024:5692",
    "cpe" : "cpe:/o:redhat:rhel_aus:8.6",
    "package" : "kernel-0:4.18.0-372.119.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Telecommunications Update Service",
    "release_date" : "2024-08-21T00:00:00Z",
    "advisory" : "RHSA-2024:5692",
    "cpe" : "cpe:/o:redhat:rhel_tus:8.6",
    "package" : "kernel-0:4.18.0-372.119.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions",
    "release_date" : "2024-08-21T00:00:00Z",
    "advisory" : "RHSA-2024:5692",
    "cpe" : "cpe:/o:redhat:rhel_e4s:8.6",
    "package" : "kernel-0:4.18.0-372.119.1.el8_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8.8 Extended Update Support",
    "release_date" : "2024-09-24T00:00:00Z",
    "advisory" : "RHSA-2024:6993",
    "cpe" : "cpe:/o:redhat:rhel_eus:8.8",
    "package" : "kernel-0:4.18.0-477.74.1.el8_8"
  } ],
  "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 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-2021-47356\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47356\nhttps://lore.kernel.org/linux-cve-announce/2024052142-CVE-2021-47356-a3d4@gregkh/T" ],
  "name" : "CVE-2021-47356",
  "mitigation" : {
    "value" : "Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.",
    "lang" : "en:us"
  },
  "csaw" : false
}