Vulnerability CVE-2021-4001

Vulnerability Name:

CVE-2021-4001 (CCN-217996)

Assigned:

2021-11-15

Published:

2021-11-15

Updated:

2022-11-16

Summary:

A race condition was found in the Linux kernel's ebpf verifier between bpf_map_update_elem and bpf_map_freeze due to a missing lock in kernel/bpf/syscall.c. In this flaw, a local user with a special privilege (cap_sys_admin or cap_bpf) can modify the frozen mapped address space. This flaw affects kernel versions prior to 5.16 rc2.

CVSS v3 Severity:

4.1 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N)
3.6 Low (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C)

Exploitability Metrics:	Attack Vector (AV): Local Attack Complexity (AC): High Privileges Required (PR): High User Interaction (UI): None
Scope:	Scope (S): Unchanged
Impact Metrics:	Confidentiality (C): None Integrity (I): High Availibility (A): None

4.4 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N)
3.9 Low (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C)

Exploitability Metrics:	Attack Vector (AV): Local Attack Complexity (AC): Low Privileges Required (PR): High User Interaction (UI): None
Scope:	Scope (S): Unchanged
Impact Metrics:	Confidentiality (C): None Integrity (I): High Availibility (A): None

CVSS v2 Severity:

4.7 Medium (CVSS v2 Vector: AV:L/AC:M/Au:N/C:N/I:C/A:N)

Exploitability Metrics:	Access Vector (AV): Local Access Complexity (AC): Medium Authentication (Au): None
Impact Metrics:	Confidentiality (C): None Integrity (I): Complete Availibility (A): None

4.6 Medium (CCN CVSS v2 Vector: AV:L/AC:L/Au:S/C:N/I:C/A:N)

Exploitability Metrics:	Access Vector (AV): Local Access Complexity (AC): Low Athentication (Au): Single_Instance
Impact Metrics:	Confidentiality (C): None Integrity (I): Complete Availibility (A): None

Vulnerability Type:

CWE-367

Vulnerability Consequences:

Bypass Security

References:

Source: MITRE
Type: CNA
CVE-2021-4001

Source: CCN
Type: Red Hat Bugzilla Bug 2025645
(CVE-2021-4001) - CVE-2021-4001 kernel: race condition when the EBPF map is frozen

Source: MISC
Type: Issue Tracking, Patch, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2025645

Source: XF
Type: UNKNOWN
linux-kernel-cve20214001-sec-bypass(217996)

Source: CCN
Type: Linux Kernel GIT Repository
bpf: Fix toctou on read-only map's constant scalar tracking

Source: MISC
Type: Patch, Third Party Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=353050be4c19e102178ccc05988101887c25ae53

Source: CCN
Type: SNYK-CENTOS8-KERNELTOOLS-1974217
Time-of-check Time-of-use (TOCTOU)

Source: CCN
Type: SNYK-UNMANAGED-TORVALDSLINUX-2936268
Race Condition

Vulnerable Configuration:

Configuration 1:

cpe:/o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:*

OR cpe:/o:linux:linux_kernel:*:*:*:*:*:*:*:* (Version <= 5.15)

Configuration CCN 1:

cpe:/a:linux:linux_kernel:5.15:-:*:*:*:*:*:*

Denotes that component is vulnerable

Oval Definitions

Definition ID	Class	Title	Last Modified
oval:org.opensuse.security:def:8029	P	kernel-docs-5.14.21-150500.53.2 on GA media (Moderate)	2023-06-20
oval:org.opensuse.security:def:7539	P	kernel-64kb-5.14.21-150500.53.2 on GA media (Moderate)	2023-06-12
oval:org.opensuse.security:def:7593	P	libgstphotography-1_0-0-1.22.0-150500.1.3 on GA media (Moderate)	2023-06-12
oval:org.opensuse.security:def:7720	P	mozilla-nspr-32bit-4.34.1-150000.3.26.1 on GA media (Moderate)	2023-06-12
oval:org.opensuse.security:def:8090	P	reiserfs-kmp-default-5.14.21-150500.53.2 on GA media (Moderate)	2023-06-12
oval:org.opensuse.security:def:3567	P	libXtst6-1.2.2-7.1 on GA media (Moderate)	2022-06-28
oval:org.opensuse.security:def:3398	P	wpa_supplicant-2.6-15.10.1 on GA media (Moderate)	2022-06-28
oval:org.opensuse.security:def:3448	P	busybox-1.21.1-3.3 on GA media (Moderate)	2022-06-28
oval:org.opensuse.security:def:3743	P	perl-32bit-5.18.2-12.20.1 on GA media (Moderate)	2022-06-28
oval:org.opensuse.security:def:3453	P	clamav-0.101.3-1.19 on GA media (Moderate)	2022-06-28
oval:org.opensuse.security:def:95078	P	reiserfs-kmp-default-5.14.21-150400.22.1 on GA media (Moderate)	2022-06-22
oval:org.opensuse.security:def:95083	P	kernel-azure-5.14.21-150400.12.1 on GA media (Moderate)	2022-06-22
oval:org.opensuse.security:def:94590	P	kernel-64kb-5.14.21-150400.22.1 on GA media (Moderate)	2022-06-22
oval:org.opensuse.security:def:95197	P	kernel-default-extra-5.14.21-150400.22.1 on GA media (Moderate)	2022-06-22
oval:org.opensuse.security:def:95028	P	kernel-docs-5.14.21-150400.22.1 on GA media (Moderate)	2022-06-22
oval:org.opensuse.security:def:2960	P	kernel-64kb-5.14.21-150400.22.1 on GA media (Moderate)	2022-06-22
oval:org.opensuse.security:def:4601	P	Security update for the Linux Kernel (Live Patch 19 for SLE 12 SP5) (Important)	2022-05-10
oval:org.opensuse.security:def:102030	P	Security update for the Linux Kernel (Live Patch 3 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:1450	P	Security update for the Linux Kernel (Live Patch 3 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:102034	P	Security update for the Linux Kernel (Live Patch 7 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:102027	P	Security update for the Linux Kernel (Live Patch 1 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:1454	P	Security update for the Linux Kernel (Live Patch 7 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:1447	P	Security update for the Linux Kernel (Live Patch 1 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:102031	P	Security update for the Linux Kernel (Live Patch 5 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:1451	P	Security update for the Linux Kernel (Live Patch 5 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:102035	P	Security update for the Linux Kernel (Live Patch 10 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:102028	P	Security update for the Linux Kernel (Live Patch 2 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:1455	P	Security update for the Linux Kernel (Live Patch 10 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:1448	P	Security update for the Linux Kernel (Live Patch 2 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:102032	P	Security update for the Linux Kernel (Live Patch 4 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:101949	P	Security update for the Linux Kernel (Live Patch 9 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:1452	P	Security update for the Linux Kernel (Live Patch 4 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:1296	P	Security update for the Linux Kernel (Live Patch 9 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:102029	P	Security update for the Linux Kernel (Live Patch 0 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:1449	P	Security update for the Linux Kernel (Live Patch 0 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:102033	P	Security update for the Linux Kernel (Live Patch 6 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:1453	P	Security update for the Linux Kernel (Live Patch 6 for SLE 15 SP3) (Important)	2022-03-29
oval:org.opensuse.security:def:118920	P	Security update for the Linux Kernel (Important)	2022-01-26
oval:org.opensuse.security:def:119225	P	Security update for the Linux Kernel (Important)	2022-01-26
oval:org.opensuse.security:def:118646	P	Security update for the Linux Kernel (Important)	2022-01-26
oval:org.opensuse.security:def:119415	P	Security update for the Linux Kernel (Important)	2022-01-26
oval:org.opensuse.security:def:42189	P	Security update for the Linux Kernel (Important)	2022-01-26
oval:org.opensuse.security:def:118730	P	Security update for the Linux Kernel (Important)	2022-01-26
oval:org.opensuse.security:def:119600	P	Security update for the Linux Kernel (Important)	2022-01-26
oval:org.opensuse.security:def:118182	P	Security update for the Linux Kernel (Important)	2022-01-26
oval:org.opensuse.security:def:118438	P	Security update for the Linux Kernel (Important)	2022-01-25
oval:org.opensuse.security:def:42186	P	Security update for the Linux Kernel (Important)	2022-01-25
oval:org.opensuse.security:def:1316	P	Security update for the Linux Kernel (Important)	2022-01-19
oval:org.opensuse.security:def:101837	P	Security update for the Linux Kernel (Important)	2022-01-19
oval:org.opensuse.security:def:99198	P	(Important)	2022-01-19
oval:org.opensuse.security:def:1159	P	Security update for the Linux Kernel (Important)	2022-01-19
oval:org.opensuse.security:def:100400	P	(Important)	2022-01-19
oval:org.opensuse.security:def:102306	P	Security update for the Linux Kernel (Important)	2022-01-19
oval:org.opensuse.security:def:101892	P	Security update for the Linux Kernel (Important)	2022-01-19
oval:org.opensuse.security:def:1748	P	Security update for the Linux Kernel (Important)	2022-01-19
oval:org.opensuse.security:def:99472	P	(Important)	2022-01-19
oval:org.opensuse.security:def:1232	P	Security update for the Linux Kernel (Important)	2022-01-19
oval:org.opensuse.security:def:100734	P	(Important)	2022-01-19
oval:org.opensuse.security:def:102351	P	Security update for the Linux Kernel (Important)	2022-01-19
oval:org.opensuse.security:def:1799	P	Security update for the Linux Kernel (Important)	2022-01-19
oval:org.opensuse.security:def:99734	P	(Important)	2022-01-19
oval:org.opensuse.security:def:101590	P	Security update for the Linux Kernel (Important)	2022-01-19
oval:org.opensuse.security:def:859	P	Security update for the Linux Kernel (Important)	2022-01-19
oval:org.opensuse.security:def:42268	P	Security update for the Linux Kernel (Important)	2022-01-19
oval:org.opensuse.security:def:101969	P	Security update for the Linux Kernel (Important)	2022-01-19
oval:org.opensuse.security:def:100062	P	(Important)	2022-01-19
oval:org.opensuse.security:def:102159	P	Security update for the Linux Kernel (Important)	2022-01-14
oval:org.opensuse.security:def:1602	P	Security update for the Linux Kernel (Important)	2022-01-14
oval:org.opensuse.security:def:42355	P	Security update for the Linux Kernel (Important)	2022-01-14
oval:org.opensuse.security:def:68809	P	Security update for the Linux Kernel (Important)	2022-01-14
oval:org.opensuse.security:def:68682	P	Security update for the Linux Kernel (Important)	2022-01-11
oval:org.opensuse.security:def:76456	P	Security update for the Linux Kernel (Important)	2022-01-11
oval:org.opensuse.security:def:111873	P	Security update for the Linux Kernel (Important)	2022-01-11
oval:org.opensuse.security:def:67388	P	Security update for the Linux Kernel (Important)	2022-01-11
oval:org.opensuse.security:def:6299	P	Security update for the Linux Kernel (Important)	2022-01-11
oval:org.opensuse.security:def:102125	P	Security update for the Linux Kernel (Important)	2022-01-11
oval:org.opensuse.security:def:1564	P	Security update for the Linux Kernel (Important)	2022-01-11
oval:org.opensuse.security:def:68387	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:76445	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:7298	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:111858	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:67377	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:10710	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:6288	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:73954	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:64832	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:67580	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:74758	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:6491	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:70850	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:65690	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07
oval:org.opensuse.security:def:8402	P	Security update for the Linux Kernel (Important) (in QA)	2022-01-07

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