PT-2018-2968 · Linux+5 · Linux Kernel+5

Chenxiang · CVE-2018-20836 · Published 2018-09-25 · Updated 2022-11-03

Positive Technologies (AI Summary)

CVSS v2.0

9.3

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 4.20

Description The issue is related to errors in synchronization when using a shared resource, specifically a race condition in the smp task timedout() and smp task done() functions in the drivers/scsi/libsas/sas expander.c file. This could allow a remote attacker to impact the confidentiality, integrity, and availability of protected information. The race condition leads to a use-after-free scenario.

Recommendations For Linux kernel versions prior to 4.20, update to version 4.20 or later to resolve the issue. As a temporary workaround, consider restricting access to the sas expander.c file or the affected functions smp task timedout() and smp task done() to minimize the risk of exploitation.

Fix

Use After Free

Race Condition

Weakness Enumeration

CWE-416

CWE-362

Related Identifiers

ALT-PU-2019-1139

ALT-PU-2019-1363

ALT-PU-2019-1794

BDU:2019-02826

CESA-2020_4060

CVE-2018-20836

DLA-1884-1

DLA-1885-1

DSA-4495-1

DSA-4497-1

OPENSUSE-SU-2019:1716-1

OPENSUSE-SU-2019:1757-1

OPENSUSE-SU-2019_1716-1

OPENSUSE-SU-2019_1757-1

RHSA-2020:4060

RHSA-2020:4062

RHSA-2020:5656

RHSA-2020_4060

RHSA-2020_4062

RHSA-2021:0019

SUSE-SU-2019:14127-1

SUSE-SU-2019:1823-1

SUSE-SU-2019:1823-2

SUSE-SU-2019:1829-1

SUSE-SU-2019:1851-1

SUSE-SU-2019:1852-1

SUSE-SU-2019:1854-1

SUSE-SU-2019:1855-1

SUSE-SU-2019:1870-1

SUSE-SU-2019:2069-1

SUSE-SU-2019:2430-1

SUSE-SU-2019:2450-1

SUSE-SU-2019_14127-1

SUSE-SU-2019_1823-1

SUSE-SU-2019_1823-2

SUSE-SU-2019_1852-1

SUSE-SU-2019_1854-1

SUSE-SU-2019_1870-1

SUSE-SU-2020:1084-1

SUSE-SU-2020:1118-1

SUSE-SU-2020:1142-1

SUSE-SU-2020_1118-1

SUSE-SU-2020_1142-1

USN-4076-1

Affected Products

Alt Linux

Centos

Linux Kernel

Red Hat

Suse

Ubuntu

References · 872

• https://github.com/torvalds/linux/commit/b90cd6f2b905905fb42671009dc0e27c310a16ae · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2018-20836?cpeVersion=2.2 · Security Note
• https://osv.dev/vulnerability/SUSE-SU-2019:1870-1 · Vendor Advisory
• http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00014.html · Vendor Advisory
• http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00025.html · Vendor Advisory
• https://debian.org/security/2019/dsa-4495 · Vendor Advisory
• https://osv.dev/vulnerability/DSA-4495-1 · Vendor Advisory
• https://bdu.fstec.ru/vul/2019-02826 · Security Note
• https://osv.dev/vulnerability/SUSE-SU-2020:1084-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2019:1855-1 · Vendor Advisory
• https://linux.oracle.com/errata/ELSA-2019-4685.html · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2019:1829-1 · Vendor Advisory
• https://usn.ubuntu.com/4076-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2018-20836 · Vendor Advisory
• https://linux.oracle.com/errata/ELSA-2019-4670.html · Vendor Advisory