CVE-2019-19447

Public on

Last Modified: UTC

ModerateModerate ImpactWhat does this mean?

Insights vulnerability analysis

View exposed systems

Description

A flaw was found in the Linux kernel's ext4_unlink function. An attacker could corrupt memory or escalate privileges when deleting a file from a recently unmounted specially crafted ext4 filesystem, including local, USB, and iSCSI.

A flaw was found in the Linux kernel's ext4_unlink function. An attacker could corrupt memory or escalate privileges when deleting a file from a recently unmounted specially crafted ext4 filesystem, including local, USB, and iSCSI.

Mitigation

Ext4 filesytems are built into the kernel so it is not possible to prevent the kernel module from loading. However, this flaw can be prevented by disallowing mounting of untrusted filesystems.

As mounting is a privileged operation, (except for device hotplug) removing the ability for mounting and unmounting will prevent this flaw from being exploited.

Additional information

  • Bugzilla 1781679: kernel: mounting a crafted ext4 filesystem image, performing some operations, and unmounting can lead to a use-after-free in ext4_put_super in fs/ext4/super.c
  • CWE-416: Use After Free
  • FAQ: Frequently asked questions about CVE-2019-19447

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

7.8

7.8

Attack Vector

Local

Local

Attack Complexity

Low

Low

Privileges Required

None

None

User Interaction

Required

Required

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:L/PR:N/UI:R/S:U/C:H/I:H/A:H

NVD: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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?

What can I do if my product is listed as "Will not fix"?

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?

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

Want to get errata notifications? Sign up here.