CVE-2023-4623 (GCVE-0-2023-4623)

Vulnerability from cvelistv5 – Published: 2023-09-06 13:56 – Updated: 2025-02-27 21:00
VLAI
Title
Use-after-free in Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component
Summary
A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation. If a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free. We recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
Assigner
References
Impacted products
Vendor Product Version
Linux Kernel Affected: 2.6.12 , < 6.6 (custom)
Create a notification for this product.
Date Public
2023-08-26 01:57
Credits
Budimir Markovic
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-02T07:31:06.625Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "patch",
              "x_transferred"
            ],
            "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2023-4623",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-02-26T21:52:35.435762Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-02-27T21:00:32.991Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageName": "kernel",
          "product": "Kernel",
          "repo": "https://git.kernel.org",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6.6",
              "status": "affected",
              "version": "2.6.12",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "user": "00000000-0000-4000-9000-000000000000",
          "value": "Budimir Markovic"
        }
      ],
      "datePublic": "2023-08-26T01:57:54.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "A use-after-free vulnerability in the Linux kernel\u0027s net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation.\n\nIf a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free.\n\nWe recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-233",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-233 Privilege Escalation"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-416",
              "description": "CWE-416 Use After Free",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2024-01-11T19:06:55.765Z",
        "orgId": "14ed7db2-1595-443d-9d34-6215bf890778",
        "shortName": "Google"
      },
      "references": [
        {
          "tags": [
            "patch"
          ],
          "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f"
        },
        {
          "url": "https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f"
        },
        {
          "url": "https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html"
        },
        {
          "url": "http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html"
        },
        {
          "url": "https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Use-after-free in Linux kernel\u0027s net/sched: sch_hfsc (HFSC qdisc traffic control) component",
      "x_generator": {
        "engine": "Vulnogram 0.1.0-dev"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "14ed7db2-1595-443d-9d34-6215bf890778",
    "assignerShortName": "Google",
    "cveId": "CVE-2023-4623",
    "datePublished": "2023-09-06T13:56:57.295Z",
    "dateReserved": "2023-08-30T11:58:12.267Z",
    "dateUpdated": "2025-02-27T21:00:32.991Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2023-4623",
      "date": "2026-06-05",
      "epss": "0.00017",
      "percentile": "0.04598"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2023-4623\",\"sourceIdentifier\":\"cve-coordination@google.com\",\"published\":\"2023-09-06T14:15:12.357\",\"lastModified\":\"2025-03-20T16:59:51.550\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A use-after-free vulnerability in the Linux kernel\u0027s net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation.\\n\\nIf a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free.\\n\\nWe recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.\"},{\"lang\":\"es\",\"value\":\"Una vulnerabilidad de Use After Free en el componente net/sched: sch_hfsc (HFSC qdisc traffic control) del kernel de Linux puede ser explotada para conseguir una escalada local de privilegios. Si una clase con una curva de compartici\u00f3n de enlaces (es decir, con la flag HFSC_FSC establecida) tiene un padre sin una curva de compartici\u00f3n de enlaces, entonces init_vf() llamar\u00e1 a vttree_insert() en el padre, pero vttree_remove() se omitir\u00e1 en update_vf(). Esto deja un puntero colgando que puede causar un Use-After-Free. Recomendamos actualizar desde el commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f. \"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"cve-coordination@google.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9},{\"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:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"weaknesses\":[{\"source\":\"cve-coordination@google.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-416\"}]},{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-416\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"2.6.12\",\"versionEndExcluding\":\"4.14.327\",\"matchCriteriaId\":\"97B268FE-B571-4275-BB68-92D593881C9E\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"4.15\",\"versionEndExcluding\":\"4.19.295\",\"matchCriteriaId\":\"D419C7D6-F33D-4EF8-8950-1CB5DDF6A55D\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"4.20\",\"versionEndExcluding\":\"5.4.257\",\"matchCriteriaId\":\"834BD148-28EC-43A4-A4F5-458124A1E39F\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"5.5\",\"versionEndExcluding\":\"5.10.195\",\"matchCriteriaId\":\"C385B650-53DB-4BFB-83D1-1D8FADF653EF\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"5.11\",\"versionEndExcluding\":\"5.15.132\",\"matchCriteriaId\":\"5913891D-409A-4EEC-9231-F2EF5A493BC7\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"5.16\",\"versionEndExcluding\":\"6.1.53\",\"matchCriteriaId\":\"B20754AF-3B8C-4574-A70D-EC24933810E5\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.2\",\"versionEndExcluding\":\"6.4.16\",\"matchCriteriaId\":\"C3039EA3-F6CA-43EF-9F17-81A7EC6841EF\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.5\",\"versionEndExcluding\":\"6.5.3\",\"matchCriteriaId\":\"880C803A-BEAE-4DA0-8A59-AC023F7B4EE3\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"07B237A9-69A3-4A9C-9DA0-4E06BD37AE73\"}]}]}],\"references\":[{\"url\":\"http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html\",\"source\":\"cve-coordination@google.com\",\"tags\":[\"Third Party Advisory\",\"VDB Entry\"]},{\"url\":\"https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f\",\"source\":\"cve-coordination@google.com\",\"tags\":[\"Issue Tracking\",\"Mailing List\",\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f\",\"source\":\"cve-coordination@google.com\",\"tags\":[\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html\",\"source\":\"cve-coordination@google.com\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html\",\"source\":\"cve-coordination@google.com\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]},{\"url\":\"http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\",\"VDB Entry\"]},{\"url\":\"https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Issue Tracking\",\"Mailing List\",\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]}]}}",
    "vulnrichment": {
      "containers": "{\"cna\": {\"providerMetadata\": {\"orgId\": \"14ed7db2-1595-443d-9d34-6215bf890778\", \"shortName\": \"Google\", \"dateUpdated\": \"2024-01-11T19:06:55.765Z\"}, \"title\": \"Use-after-free in Linux kernel\u0027s net/sched: sch_hfsc (HFSC qdisc traffic control) component\", \"datePublic\": \"2023-08-26T01:57:54.000Z\", \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"cweId\": \"CWE-416\", \"description\": \"CWE-416 Use After Free\", \"type\": \"CWE\"}]}], \"impacts\": [{\"capecId\": \"CAPEC-233\", \"descriptions\": [{\"lang\": \"en\", \"value\": \"CAPEC-233 Privilege Escalation\"}]}], \"affected\": [{\"vendor\": \"Linux\", \"product\": \"Kernel\", \"packageName\": \"kernel\", \"repo\": \"https://git.kernel.org\", \"versions\": [{\"status\": \"affected\", \"version\": \"2.6.12\", \"lessThan\": \"6.6\", \"versionType\": \"custom\"}], \"defaultStatus\": \"unaffected\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"A use-after-free vulnerability in the Linux kernel\u0027s net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation.\\n\\nIf a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free.\\n\\nWe recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.\"}], \"references\": [{\"url\": \"https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f\", \"tags\": [\"patch\"]}, {\"url\": \"https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f\"}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html\"}, {\"url\": \"http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html\"}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html\"}], \"metrics\": [{\"format\": \"CVSS\", \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}], \"cvssV3_1\": {\"version\": \"3.1\", \"attackVector\": \"LOCAL\", \"attackComplexity\": \"LOW\", \"privilegesRequired\": \"LOW\", \"userInteraction\": \"NONE\", \"scope\": \"UNCHANGED\", \"confidentialityImpact\": \"HIGH\", \"integrityImpact\": \"HIGH\", \"availabilityImpact\": \"HIGH\", \"baseSeverity\": \"HIGH\", \"baseScore\": 7.8, \"vectorString\": \"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\"}}], \"credits\": [{\"lang\": \"en\", \"value\": \"Budimir Markovic\", \"user\": \"00000000-0000-4000-9000-000000000000\", \"type\": \"finder\"}], \"source\": {\"discovery\": \"EXTERNAL\"}, \"x_generator\": {\"engine\": \"Vulnogram 0.1.0-dev\"}}, \"adp\": [{\"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2024-08-02T07:31:06.625Z\"}, \"title\": \"CVE Program Container\", \"references\": [{\"url\": \"https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f\", \"tags\": [\"patch\", \"x_transferred\"]}, {\"url\": \"https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html\", \"tags\": [\"x_transferred\"]}, {\"url\": \"http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html\", \"tags\": [\"x_transferred\"]}]}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2023-4623\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2025-02-26T21:52:35.435762Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2025-02-26T20:38:23.976Z\"}}]}",
      "cveMetadata": "{\"cveId\": \"CVE-2023-4623\", \"assignerOrgId\": \"14ed7db2-1595-443d-9d34-6215bf890778\", \"state\": \"PUBLISHED\", \"assignerShortName\": \"Google\", \"dateReserved\": \"2023-08-30T11:58:12.267Z\", \"datePublished\": \"2023-09-06T13:56:57.295Z\", \"dateUpdated\": \"2025-02-27T21:00:32.991Z\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.1"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.