PT-2021-3824 · Linux+5 · Linux Kernel+5

Butt3Rflyh4Ck · Published 2021-05-31 · Updated 2023-05-17 · CVE-2021-38208

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 5.12.10

Description The issue is related to a NULL pointer dereference in the net/nfc/llcp sock.c component of the Linux kernel. It can be exploited by local unprivileged users to cause a denial of service by making a getsockname call after a certain type of failure of a bind call, such as when LLCP SAP MAX is used as SAP. This can lead to a denial of service (NULL pointer dereference and BUG).

Recommendations For Linux kernel versions prior to 5.12.10, update to version 5.12.10 or later to resolve the issue. As a temporary workaround, consider restricting access to the getsockname() function and the bind() call in the net/nfc/llcp sock.c component to minimize the risk of exploitation.

Exploit

Fix

DoS

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

ALT-PU-2021-1990

ALT-PU-2021-2026

ALT-PU-2021-2315

ALT-PU-2021-2326

ALT-PU-2021-2330

ALT-PU-2021-3481

ALT-PU-2022-1240

ALT-PU-2022-1419

ALT-PU-2022-1421

ALT-PU-2023-1814

AZL-6592

BDU:2021-04152

CVE-2021-38208

DLA-2689-1

DLA-2690-1

MGASA-2021-0257

MGASA-2021-0258

OESA-2021-1318

OPENSUSE-SU-2022_1676-1

OPENSUSE-SU-2022_1687-1

OPENSUSE-SU-2022_2111-1

SUSE-SU-2022:1651-1

SUSE-SU-2022:1668-1

SUSE-SU-2022:1669-1

SUSE-SU-2022:1676-1

SUSE-SU-2022:1686-1

SUSE-SU-2022:1687-1

SUSE-SU-2022:2077-1

SUSE-SU-2022:2082-1

SUSE-SU-2022:2083-1

SUSE-SU-2022:2103-1

SUSE-SU-2022:2111-1

SUSE-SU-2022_1651-1

SUSE-SU-2022_1669-1

SUSE-SU-2022_1676-1

SUSE-SU-2022_1686-1

SUSE-SU-2022_1687-1

USN-5050-1

USN-5343-1

Affected Products

Alt Linux

Astra Linux

Linuxmint

Linux Kernel

Suse

Ubuntu

References · 272

• 🔥 https://github.com/torvalds/linux/commit/4ac06a1e013cf5fdd963317ffd3b968560f33bba · Exploit
• https://ubuntu.com/security/CVE-2021-38208 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-38205 · Security Note
• https://ubuntu.com/security/CVE-2021-38160 · Vendor Advisory
• https://osv.dev/vulnerability/AZL-6592 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-42008 · Vendor Advisory
• https://osv.dev/vulnerability/OESA-2021-1318 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-38199 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2021-38208 · Security Note
• https://ubuntu.com/security/CVE-2021-29650 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-38209 · Security Note
• https://ubuntu.com/security/CVE-2021-45485 · Vendor Advisory
• https://osv.dev/vulnerability/USN-5343-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-43389 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-3564 · Vendor Advisory