PT-2021-2548 · Linux+1 · Linux Kernel+1

Published 2021-04-06 · Updated 2023-05-17 · CVE-2021-30178

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/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 5.11.11

Description: The issue is related to a NULL pointer dereference in the synic get function in arch/x86/kvm/hyperv.c for certain accesses to the SynIC Hyper-V context. This could allow an attacker to cause a denial of service.

Recommendations: For Linux kernel versions prior to 5.11.11, update to a version 5.11.11 or later to resolve the issue. As a temporary workaround, consider restricting access to the synic get function in arch/x86/kvm/hyperv.c to minimize the risk of exploitation.

Fix

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

ALT-PU-2021-1609

ALT-PU-2021-1629

ALT-PU-2021-1869

ALT-PU-2021-1888

ALT-PU-2021-1896

ALT-PU-2022-1240

ALT-PU-2022-1419

ALT-PU-2022-1421

ALT-PU-2023-1814

AZL-6556

BDU:2021-01955

CVE-2021-30178

Affected Products

Alt Linux

Linux Kernel

References · 15

• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/W5YFGIIF24475A2LNW3UWHW2SNCS3G7M · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IJ5GEETMX3ERQ4DF3GSS2XPNSOOK44OB · Vendor Advisory
• https://osv.dev/vulnerability/AZL-6556 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TGQDVYCDM3F5VXUZIADIV2ERL3AJXNJS · Vendor Advisory
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=919f4ebc598701670e80e31573a58f1f2d2bf918 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-30178 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-30178 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-30178 · Security Note
• https://bdu.fstec.ru/vul/2021-01955 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2021-30178 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-30178 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-30178 · Security Note
• https://t.me/cvenotify/13530 · Telegram Post
• https://t.me/cvenotify/12775 · Telegram Post
• https://git.kernel.org/linus/919f4ebc598701670e80e31573a58f1f2d2bf918 · Note