{
  "threat_severity" : "Moderate",
  "public_date" : "2024-05-21T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: tty: Fix out-of-bound vmalloc access in imageblit",
    "id" : "2282357",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2282357"
  },
  "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-125",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\ntty: Fix out-of-bound vmalloc access in imageblit\nThis issue happens when a userspace program does an ioctl\nFBIOPUT_VSCREENINFO passing the fb_var_screeninfo struct\ncontaining only the fields xres, yres, and bits_per_pixel\nwith values.\nIf this struct is the same as the previous ioctl, the\nvc_resize() detects it and doesn't call the resize_screen(),\nleaving the fb_var_screeninfo incomplete. And this leads to\nthe updatescrollmode() calculates a wrong value to\nfbcon_display->vrows, which makes the real_y() return a\nwrong value of y, and that value, eventually, causes\nthe imageblit to access an out-of-bound address value.\nTo solve this issue I made the resize_screen() be called\neven if the screen does not need any resizing, so it will\n\"fix and fill\" the fb_var_screeninfo independently.", "A vulnerability was found in the Linux kernel's tty subsystem within the imageblit function when a userspace program performs an ioctl operation with the FBIOPUT_VSCREENINFO command, passing a fb_var_screeninfo structure with limited fields. If the structure’s values remain unchanged from a previous ioctl call, the kernel fails to fully update the screen information, leading to incorrect calculations of screen dimensions potentially causing system crashes or instability." ],
  "statement" : "This vulnerability is rated as a moderate severity because it can lead to system crashes by accessing invalid memory addresses, it does not pose a direct threat to data security or allow unauthorized access.",
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2024-09-24T00:00:00Z",
    "advisory" : "RHSA-2024:7001",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8::nfv",
    "package" : "kernel-rt-0:4.18.0-553.22.1.rt7.363.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2024-09-24T00:00:00Z",
    "advisory" : "RHSA-2024:7000",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-553.22.1.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2024-10-30T00:00:00Z",
    "advisory" : "RHSA-2024:8617",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-427.42.1.el9_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2024-10-30T00:00:00Z",
    "advisory" : "RHSA-2024:8617",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-427.42.1.el9_4"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Extended Update Support",
    "release_date" : "2024-08-14T00:00:00Z",
    "advisory" : "RHSA-2024:5364",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.2",
    "package" : "kernel-0:5.14.0-284.79.1.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Extended Update Support",
    "release_date" : "2024-08-14T00:00:00Z",
    "advisory" : "RHSA-2024:5365",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.2::nfv",
    "package" : "kernel-rt-0:5.14.0-284.79.1.rt14.364.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" : "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" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2021-47383\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47383\nhttps://lore.kernel.org/linux-cve-announce/2024052144-CVE-2021-47383-a8f4@gregkh/T" ],
  "name" : "CVE-2021-47383",
  "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
}