CVE-2018-20856

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Description

A flaw was found in the Linux kernel’s block driver implementation (blk_drain_queue() function) where a use-after-free condition could be triggered while draining the outstanding command queue in the systems block device subsystem. An attacker could use this flaw to crash the system or corrupt local memory, which may lead to privilege escalation.

A flaw was found in the Linux kernel’s block driver implementation (blk_drain_queue() function) where a use-after-free condition could be triggered while draining the outstanding command queue in the systems block device subsystem. An attacker could use this flaw to crash the system or corrupt local memory, which may lead to privilege escalation.

Additional information

  • Bugzilla 1738705: kernel: Use-after-free in __blk_drain_queue() function in block/blk-core.c
  • CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
  • FAQ: Frequently asked questions about CVE-2018-20856

Common Vulnerability Scoring System (CVSS) Score Details

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 HatNVD

CVSS v3 Base Score

7

7.8

Attack Vector

Local

Local

Attack Complexity

High

Low

Privileges Required

Low

Low

User Interaction

None

None

Scope

Unchanged

Unchanged

Confidentiality Impact

High

High

Integrity Impact

High

High

Availability Impact

High

High

CVSS v3 Vector

Red Hat: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

NVD: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

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What can I do if my product is listed as "Fix deferred"?

What is a mitigation?

I have a Red Hat product but it is not in the above list, is it affected?

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