PT-2020-6690 · Linux+4 · Linux Kernel+4

Published 2020-03-27 · Updated 2023-02-15 · CVE-2020-36557

Positive Technologies (AI Summary)

CVSS v2.0

10

High

Base vector

AV:N/AC:L/Au:N/C:C/I:C/A:C

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 5.6.2

Description A race condition between the VT DISALLOCATE ioctl and closing/opening of ttys could lead to a use-after-free. This issue is related to the implementation of the VT DISALLOCATE call in the Linux kernel, which can cause a use-after-free when loading the tty utility. Exploitation of this issue could allow a remote attacker to cause a denial of service.

Recommendations For Linux kernel versions prior to 5.6.2, update to version 5.6.2 or later to resolve the issue. As a temporary workaround, consider restricting access to the VT DISALLOCATE ioctl to minimize the risk of exploitation.

Fix

Race Condition

Use After Free

Weakness Enumeration

CWE-362

CWE-416

Related Identifiers

ALT-PU-2020-1671

ALT-PU-2020-1673

ALT-PU-2020-1761

ALT-PU-2020-1917

ALT-PU-2020-2153

ALT-PU-2020-2164

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:2022-04677

CESA-2021_1578

CVE-2020-36557

OPENSUSE-SU-2022_2741-1

OPENSUSE-SU-2022_2827-1

OPENSUSE-SU-2022_2875-1

RHSA-2021:1578

RHSA-2021_1578

SUSE-SU-2022:2719-1

SUSE-SU-2022:2720-1

SUSE-SU-2022:2721-1

SUSE-SU-2022:2723-1

SUSE-SU-2022:2741-1

SUSE-SU-2022:2809-1

SUSE-SU-2022:2827-1

SUSE-SU-2022:2840-1

SUSE-SU-2022:2875-1

SUSE-SU-2022:2875-2

SUSE-SU-2022:2892-1

SUSE-SU-2022:2892-2

SUSE-SU-2022:2910-1

SUSE-SU-2022:3274-1

SUSE-SU-2022:4027-1

SUSE-SU-2022:4129-1

SUSE-SU-2023:0416-1

Affected Products

Alt Linux

Centos

Linux Kernel

Red Hat

Suse

References · 275

• https://nvd.nist.gov/vuln/detail/CVE-2020-36557 · Security Note
• https://osv.dev/vulnerability/SUSE-SU-2022:2875-1 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2020-36557 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2022:2910-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2022:2827-1 · Vendor Advisory
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.6.2 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2022:2875-2 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2022:2720-1 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2020-36557 · Vendor Advisory
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ca4463bf8438b403596edd0ec961ca0d4fbe0220 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2022:2721-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2022:2892-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2022:2719-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2022:2723-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2022:2892-2 · Vendor Advisory