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 

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    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-06-28T06:47:55+00:00",
      "cve": "CVE-2023-4623",
      "id": "CVE-2023-4623",
      "initial_release_date": "2023-09-06T00:00:00+00:00",
      "product_status:fixed": "1798",
      "product_status:known_affected": "36",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: net/sched: sch_hfsc UAF",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2023/cve-2023-4623.json",
      "version": "3"
    },
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      "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"
    }
  }
}



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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.