CVE-2019-16233

Description

A flaw was found in the Linux kernel. A NULL pointer dereference flaw was found in the QLOGIC drivers for HBA. A call to alloc_workqueue return was not validated and can cause a denial of service. The highest threat from this vulnerability is to system availability.

Mitigation

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score4.14.1N/A
Attack VectorLocalLocalN/A
Attack ComplexityHighHighN/A
Privileges RequiredHighHighN/A
User InteractionNoneNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityNoneNoneN/A
Integrity ImpactNoneNoneN/A
Availability ImpactHighHighN/A

Vector

Red Hat: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H

NVD: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H

Red Hat CVSS v3 Score Explanation

This flaw exploitation will need some per-conditions,

  • That is there should be a memory pressure in kernel space which will cause 'kzalloc' to fail and in turn 'alloc_workqueue' will fail , making 'AC:H'.

  • Attacker will have access to the shell and should have atleast a local account. 'AV:L'

  • Attacker should have an access privilege , a special user (or a root) to exploit , 'PR:H' to access HBA device.

Understanding the Weakness (CWE)

Availability

Technical Impact: DoS: Crash, Exit, or Restart

NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.

Integrity,Confidentiality

Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory

In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.

Frequently Asked Questions

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