CVE-2021-3752 json
A use-after-free flaw was found in the Linux kernel’s Bluetooth subsystem in the way user calls connect to the socket and disconnect simult…
published 2022-02-16 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-27027
- cvss
- 7.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.7%
- EPSS 1.7% chance of exploitation in 30 days, percentile 77%
- public exploits
- 0
- none known
Summary
A use-after-free flaw was found in the Linux kernel’s Bluetooth subsystem in the way user calls connect to the socket and disconnect simultaneously due to a race condition. This flaw allows a user to crash the system or escalate their privileges. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Patch / fix
- linux linux_kernel 4.4.293, 4.9.291, 4.14.256, 4.19.218, 5.4.160, 5.10.80, 5.14.19, 5.15.3
- linux Debian 14, Debian 13, Debian 12 5.15.3-1
debian advisories DEBIAN-CVE-2021-3752
- linux Ubuntu 18.04 LTS 4.15.0-167.175
- linux Ubuntu 20.04 LTS 5.4.0-97.110
- linux-aws Ubuntu 18.04 LTS 4.15.0-1119.127
- linux-aws Ubuntu 20.04 LTS 5.4.0-1064.67
- linux-gcp Ubuntu 20.04 LTS 5.4.0-1063.67
- linux-gke Ubuntu 20.04 LTS 5.4.0-1061.64
- linux-ibm Ubuntu 20.04 LTS 5.4.0-1013.14
- linux-kvm Ubuntu 18.04 LTS 4.15.0-1106.108
ubuntu advisories UBUNTU-CVE-2021-3752
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- kernel RHEL 8 4.18.0-372.9.1.el8
- perf RHEL 8 4.18.0-372.9.1.el8
- bpftool RHEL 8 4.18.0-372.9.1.el8
- kernel-core RHEL 8 4.18.0-372.9.1.el8
- kernel-tools RHEL 8 4.18.0-372.9.1.el8
- python3-perf RHEL 8 4.18.0-372.9.1.el8
- kernel-modules RHEL 8 4.18.0-372.9.1.el8
- kernel-zfcpdump RHEL 8 4.18.0-372.9.1.el8
red hat advisories RHSA-2022:1988RHSA-2022:0622RHSA-2022:0620RHSA-2022:1975
- kernel-syms SLES for SAP 12 SP4, SLES 12 SP4-LTSS, OpenStack Cloud Crowbar 9 +1 more 4.12.14-95.83.2
- kernel-source SLES for SAP 12 SP4, SLES 12 SP4-LTSS, OpenStack Cloud Crowbar 9 +1 more 4.12.14-95.83.2
- kernel-default SLES for SAP 12 SP4, SLES 12 SP4-LTSS, SLE Live Patching 12 SP4 +3 more 4.12.14-95.83.2
- kernel-syms SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.78.1
- kernel-source SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.78.1
- kernel-default SLES for SAP 15, SLES 15-LTSS, SLE Live Patching 15 +3 more 4.12.14-150.78.1
- kernel-vanilla SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.78.1
- kernel-obs-build SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.78.2
suse advisories SUSE-SU-2021:3972-1SUSE-SU-2021:3969-1SUSE-SU-2021:3935-1SUSE-SU-2021:3929-1SUSE-SU-2021:3876-1SUSE-SU-2021:3751-1
- kernel-default openSUSE Leap 15.3 4.12.14-197.102.2
- kernel-vanilla openSUSE Leap 15.3 4.12.14-197.102.2
- kernel-kvmsmall openSUSE Leap 15.3 4.12.14-197.102.2
- kernel-zfcpdump openSUSE Leap 15.3 4.12.14-197.102.2
- kmod openSUSE Leap 15.2 25-lp152.8.3.1
- kmod-testsuite openSUSE Leap 15.2 25-lp152.8.3.2
- kernel-syms openSUSE Leap 15.2 5.3.18-lp152.95.1
- kernel-obs-qa openSUSE Leap 15.2 5.3.18-lp152.95.1
opensuse advisories openSUSE-SU-2021:3876-1openSUSE-SU-2021:1365-1openSUSE-SU-2021:1357-1openSUSE-SU-2021:3447-1openSUSE-SU-2021:3387-1openSUSE-SU-2021:3338-1
- kernel AlmaLinux 8 4.18.0-372.9.1.el8
- perf AlmaLinux 8 4.18.0-372.9.1.el8
- bpftool AlmaLinux 8 4.18.0-372.9.1.el8
- kernel-core AlmaLinux 8 4.18.0-372.9.1.el8
- kernel-tools AlmaLinux 8 4.18.0-372.9.1.el8
- python3-perf AlmaLinux 8 4.18.0-372.9.1.el8
- kernel-modules AlmaLinux 8 4.18.0-372.9.1.el8
- kernel-debug-core AlmaLinux 8 4.18.0-372.9.1.el8
almalinux advisories ALSA-2022:1988
- kernel Rocky Linux 8 4.18.0-372.9.1.el8
- kernel-rt Rocky Linux 8 4.18.0-372.9.1.rt7.166.el8
rocky linux advisories RLSA-2022:1988RLSA-2022:1975
- linux-lts Arch Linux 5.15.2-1
arch linux advisories AVG-1741
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2021-3752 updated cvss 7.0
kernel: possible use-after-free in bluetooth module
-
Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-372.9.1.el8, kernel 4.18.0-372.9.1.el8, bpftool 4.18.0-372.9.1.el8, kernel-core 4.18.0-372.9.1.el8, kernel-tools 4.18.0-372.9.1.el8, python3-perf 4.18.0-372.9.1.el8, +15 morefixed: vendor fix RHSA-2022:1988
-
Red Hat Enterprise Linux Client (v. 7) perf 3.10.0-1160.59.1.el7, kernel 3.10.0-1160.59.1.el7, bpftool 3.10.0-1160.59.1.el7, python-perf 3.10.0-1160.59.1.el7, kernel-tools 3.10.0-1160.59.1.el7, kernel-tools-libs 3.10.0-1160.59.1.el7, +2 more Red Hat Enterprise Linux Client Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.59.1.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.59.1.el7fixed: vendor fix RHSA-2022:0620
-
Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-372.9.1.el8, kernel-debuginfo-common-aarch64 4.18.0-372.9.1.el8, kernel-debuginfo-common-ppc64le 4.18.0-372.9.1.el8fixed: vendor fix RHSA-2022:1988
-
Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt 3.10.0-1160.59.1.rt56.1200.el7, kernel-rt-trace 3.10.0-1160.59.1.rt56.1200.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.59.1.rt56.1200.el7 Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt 3.10.0-1160.59.1.rt56.1200.el7, kernel-rt-kvm 3.10.0-1160.59.1.rt56.1200.el7, kernel-rt-trace 3.10.0-1160.59.1.rt56.1200.el7, kernel-rt-debug-kvm 3.10.0-1160.59.1.rt56.1200.el7, kernel-rt-trace-kvm 3.10.0-1160.59.1.rt56.1200.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.59.1.rt56.1200.el7fixed: vendor fix RHSA-2022:0622
-
Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-372.9.1.rt7.166.el8, kernel-rt-kvm 4.18.0-372.9.1.rt7.166.el8, kernel-rt-core 4.18.0-372.9.1.rt7.166.el8, kernel-rt-modules 4.18.0-372.9.1.rt7.166.el8, kernel-rt-debug-kvm 4.18.0-372.9.1.rt7.166.el8, kernel-rt-debug-core 4.18.0-372.9.1.rt7.166.el8, +4 more Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-372.9.1.rt7.166.el8, kernel-rt-core 4.18.0-372.9.1.rt7.166.el8, kernel-rt-modules 4.18.0-372.9.1.rt7.166.el8, kernel-rt-debug-core 4.18.0-372.9.1.rt7.166.el8, kernel-rt-debug-modules 4.18.0-372.9.1.rt7.166.el8, kernel-rt-modules-extra 4.18.0-372.9.1.rt7.166.el8, +2 morefixed: vendor fix RHSA-2022:1975
-
Red Hat Enterprise Linux Server (v. 7) perf 3.10.0-1160.59.1.el7, kernel 3.10.0-1160.59.1.el7, bpftool 3.10.0-1160.59.1.el7, python-perf 3.10.0-1160.59.1.el7, kernel-kdump 3.10.0-1160.59.1.el7, kernel-tools 3.10.0-1160.59.1.el7, +7 more Red Hat Enterprise Linux Server Optional (v. 7) kernel-debuginfo-common-ppc64 3.10.0-1160.59.1.el7, kernel-debuginfo-common-x86_64 3.10.0-1160.59.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-1160.59.1.el7 Red Hat Enterprise Linux Workstation (v. 7) perf 3.10.0-1160.59.1.el7, kernel 3.10.0-1160.59.1.el7, bpftool 3.10.0-1160.59.1.el7, python-perf 3.10.0-1160.59.1.el7, kernel-tools 3.10.0-1160.59.1.el7, kernel-tools-libs 3.10.0-1160.59.1.el7, +2 more Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.59.1.el7fixed: vendor fix RHSA-2022:0620
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Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 morenot affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
1.74% chance of exploitation in the next 30 days, higher than 77% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- openwall.com https://www.openwall.com/lists/oss-security/2021/09/15/4 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.1 | CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.9 | AV:A/AC:M/Au:N/C:C/I:C/A:C |
Affected products
- n/a kernel
Classification
- Weakness
- Technology feeds
References
-
oracle.com
/security-alerts/cpujul2022.html
patch, third-party-advisory
-
openwall.com
/lists/oss-security/2021/09/15/4
exploit, mailing-list, third-party-advisory
-
debian.org
/security/2022/dsa-5096
vendor-advisory, third-party-advisory
-
bugzilla.redhat.com
/show_bug.cgi?id=1999544
issue-tracking, third-party-advisory
- lore.kernel.org /lkml/20211115165435.133245729%40linuxfoundation.org/
-
lists.debian.org
/debian-lts-announce/2022/03/msg00011.html
mailing-list, third-party-advisory
-
lists.debian.org
/debian-lts-announce/2022/03/msg00012.html
mailing-list, third-party-advisory
-
security.netapp.com
/advisory/ntap-20220318-0009/
third-party-advisory
Sources
- CVE List CVE-2021-3752
- NVD CVE-2021-3752
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.