nvd-json-data-feeds/CVE-2021/CVE-2021-473xx/CVE-2021-47363.json

{
  "id": "CVE-2021-47363",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2024-05-21T15:15:22.430",
  "lastModified": "2024-12-26T17:56:27.117",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnexthop: Fix division by zero while replacing a resilient group\n\nThe resilient nexthop group torture tests in fib_nexthop.sh exposed a\npossible division by zero while replacing a resilient group [1]. The\ndivision by zero occurs when the data path sees a resilient nexthop\ngroup with zero buckets.\n\nThe tests replace a resilient nexthop group in a loop while traffic is\nforwarded through it. The tests do not specify the number of buckets\nwhile performing the replacement, resulting in the kernel allocating a\nstub resilient table (i.e, 'struct nh_res_table') with zero buckets.\n\nThis table should never be visible to the data path, but the old nexthop\ngroup (i.e., 'oldg') might still be used by the data path when the stub\ntable is assigned to it.\n\nFix this by only assigning the stub table to the old nexthop group after\nmaking sure the group is no longer used by the data path.\n\nTested with fib_nexthops.sh:\n\nTests passed: 222\nTests failed:   0\n\n[1]\n divide error: 0000 [#1] PREEMPT SMP KASAN\n CPU: 0 PID: 1850 Comm: ping Not tainted 5.14.0-custom-10271-ga86eb53057fe #1107\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014\n RIP: 0010:nexthop_select_path+0x2d2/0x1a80\n[...]\n Call Trace:\n  fib_select_multipath+0x79b/0x1530\n  fib_select_path+0x8fb/0x1c10\n  ip_route_output_key_hash_rcu+0x1198/0x2da0\n  ip_route_output_key_hash+0x190/0x340\n  ip_route_output_flow+0x21/0x120\n  raw_sendmsg+0x91d/0x2e10\n  inet_sendmsg+0x9e/0xe0\n  __sys_sendto+0x23d/0x360\n  __x64_sys_sendto+0xe1/0x1b0\n  do_syscall_64+0x35/0x80\n  entry_SYSCALL_64_after_hwframe+0x44/0xae"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: nexthop: corrige la divisi\u00f3n por cero mientras se reemplaza un grupo resistente Las pruebas de tortura del grupo resiliente de nexthop en fib_nexthop.sh expusieron una posible divisi\u00f3n por cero mientras se reemplaza un grupo resistente [1]. La divisi\u00f3n por cero ocurre cuando la ruta de datos ve un grupo de nexthop resistente con cero dep\u00f3sitos. Las pruebas reemplazan un grupo nexthop resistente en un bucle mientras el tr\u00e1fico se reenv\u00eda a trav\u00e9s de \u00e9l. Las pruebas no especifican la cantidad de dep\u00f3sitos mientras se realiza el reemplazo, lo que da como resultado que el kernel asigne una tabla resistente a resguardos (es decir, 'struct nh_res_table') con cero dep\u00f3sitos. Esta tabla nunca deber\u00eda ser visible para la ruta de datos, pero la ruta de datos a\u00fan podr\u00eda usar el antiguo grupo nexthop (es decir, 'oldg') cuando se le asigna la tabla auxiliar. Solucione este problema asignando \u00fanicamente la tabla auxiliar al antiguo grupo de nexthop despu\u00e9s de asegurarse de que la ruta de datos ya no utilice el grupo. Probado con fib_nexthops.sh: Pruebas aprobadas: 222 Pruebas fallidas: 0 [1] error de divisi\u00f3n: 0000 [#1] CPU PREEMPT SMP KASAN: 0 PID: 1850 Comunicaciones: ping No contaminado 5.14.0-custom-10271-ga86eb53057fe #1107 Nombre del hardware: PC est\u00e1ndar QEMU (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 01/04/2014 RIP: 0010:nexthop_select_path+0x2d2/0x1a80 [...] Seguimiento de llamadas: fib_select_multipath+0x79b/0x1530 fib_select_path +0x8fb/0x1c10 ip_route_output_key_hash_rcu+0x1198/0x2da0 ip_route_output_key_hash+0x190/0x340 ip_route_output_flow+0x21/0x120 raw_sendmsg+0x91d/0x2e10 inet_sendmsg+0x9e/0 xe0 __sys_sendto+0x23d/0x360 __x64_sys_sendto+0xe1/0x1b0 do_syscall_64+0x35/0x80 Entry_SYSCALL_64_after_hwframe+0x44/0xae"
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "nvd@nist.gov",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6
      }
    ]
  },
  "weaknesses": [
    {
      "source": "nvd@nist.gov",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-369"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
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              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "5.13",
              "versionEndExcluding": "5.14.9",
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  "references": [
    {
      "url": "https://git.kernel.org/stable/c/563f23b002534176f49524b5ca0e1d94d8906c40",
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}