PT-2020-4726 · Linux+6 · Linux Kernel+6

Jinoh Kang · Published 2020-10-20 · Updated 2022-04-26 · CVE-2020-27675

Positive Technologies (AI Summary)

CVSS v3.1

4.7

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions: Linux kernel versions prior to 5.9.1 Xen versions prior to 4.14.x

Description: An issue in the Linux kernel and Xen allows event-channel removal during the event-handling loop, causing a race condition. This can lead to a use-after-free or NULL pointer dereference, potentially resulting in a denial of service, as demonstrated by a dom0 crash via events for an in-reconfiguration paravirtualized device.

Recommendations: For Linux kernel versions prior to 5.9.1, update to version 5.9.1 or later to resolve the issue. For Xen versions prior to 4.14.x, update to version 4.14.x or later to resolve the issue. As a temporary workaround, consider restricting access to the events base.c component in the Xen driver to minimize the risk of exploitation.

Fix

Race Condition

Use After Free

NULL Pointer Dereference

Weakness Enumeration

CWE-362

CWE-416

CWE-476

Related Identifiers

ALT-PU-2020-3182

ALT-PU-2020-3211

ALT-PU-2020-3553

ALT-PU-2020-3570

ALT-PU-2021-1083

ALT-PU-2021-1105

ALT-PU-2021-1621

ALT-PU-2021-1656

ALT-PU-2021-1739

ALT-PU-2021-1862

ALT-PU-2021-1866

ALT-PU-2021-1870

BDU:2020-05278

CVE-2020-27675

DLA-2483-1

DLA-2494-1

MGASA-2021-0030

MGASA-2021-0031

OESA-2021-1003

SUSE-SU-2020:3272-1

SUSE-SU-2020:3281-1

SUSE-SU-2020:3491-1

SUSE-SU-2020:3532-1

SUSE-SU-2020:3544-1

USN-4679-1

USN-4680-1

USN-4681-1

USN-4751-1

Affected Products

Alt Linux

Astra Linux

Linuxmint

Linux Kernel

Suse

Ubuntu

Xen

References · 307

• https://github.com/torvalds/linux/commit/073d0552ead5bfc7a3a9c01de590e924f11b5dd2 · Patch
• https://osv.dev/vulnerability/USN-4680-1 · Vendor Advisory
• https://ubuntu.com/security/notices/USN-4680-1 · Vendor Advisory
• https://security.gentoo.org/glsa/202011-06 · Vendor Advisory
• https://osv.dev/vulnerability/DLA-2483-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2020-29569 · Vendor Advisory
• https://ubuntu.com/security/CVE-2020-27830 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2020-29569 · Security Note
• https://ubuntu.com/security/CVE-2020-27675 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3ZG6TZLD23QO3PV2AN2HB625ZX47ALTT · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2020-27675 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2020:3281-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2020-27673 · Vendor Advisory
• https://ubuntu.com/security/CVE-2020-25668 · Vendor Advisory
• https://osv.dev/vulnerability/USN-4679-1 · Vendor Advisory