CVE-2021-3752

Exp

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.

Published: 2022-02-16 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3752 is rated High Exploit Risk (71.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.75%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.72% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-3752

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-3752

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.04% 1.75% +1.72%
2 2025-11-21 0.30% 0.04% -0.27%
3 2025-11-18 — 0.30% —

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3752

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.1 3.1 HIGH
CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.2 5.9 [email protected]
7.9 2.0 HIGH
AV:A/AC:M/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:A)
Requires access to an adjacent network segment.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 5.5 10.0 [email protected]

Weakness enumeration for CVE-2021-3752

OS Trackers for CVE-2021-3752

vendor priority summary link
debian not yet assigned CVE-2021-3752 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-3752
redhat medium — https://access.redhat.com/security/cve/CVE-2021-3752
suse high CVE-2021-3752 severity important: SUSE including 652 source package names (0.16.2:kmod-25-6.10.1, 0.16.2:libkmod2-25-6.10.1, …), 1252 product×package rows across 152 product lines (Container caasp/v4/cilium, Container caasp/v4/etcd, … (152 product lines)): Fixed 1064, Known Affected 154, Known Not Affected 34. https://www.suse.com/security/cve/CVE-2021-3752/
ubuntu medium CVE-2021-3752 medium priority: Ubuntu including 168 source packages (linux, linux-allwinner, …), 2116 status rows across 15 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1640, released 216, not-affected 201, ignored 58, needed 1. https://ubuntu.com/security/CVE-2021-3752

Affected software / configurations for CVE-2021-3752

Vendor Product Version Raw CPE
linux linux_kernel >= 2.6.12, < 4.4.293 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 4.5, < 4.9.291 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 4.10, < 4.14.256 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 4.15, < 4.19.218 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 4.20, < 5.4.160 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.5, < 5.10.80 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.11, < 5.14.19 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.15, < 5.15.3 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
redhat 3scale 2.0 cpe:2.3:a:redhat:3scale:2.0:*:*:*:*:*:*:*
redhat virtualization_host 4.0 cpe:2.3:a:redhat:virtualization_host:4.0:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux_for_real_time 7 cpe:2.3:o:redhat:enterprise_linux_for_real_time:7:*:*:*:*:*:*:*
redhat enterprise_linux_for_real_time_for_nfv 7 cpe:2.3:o:redhat:enterprise_linux_for_real_time_for_nfv:7:*:*:*:*:*:*:*
netapp h300s_firmware — cpe:2.3:o:netapp:h300s_firmware:-:*:*:*:*:*:*:*
netapp h500s_firmware — cpe:2.3:o:netapp:h500s_firmware:-:*:*:*:*:*:*:*
netapp h700s_firmware — cpe:2.3:o:netapp:h700s_firmware:-:*:*:*:*:*:*:*
netapp h300e_firmware — cpe:2.3:o:netapp:h300e_firmware:-:*:*:*:*:*:*:*
netapp h500e_firmware — cpe:2.3:o:netapp:h500e_firmware:-:*:*:*:*:*:*:*
netapp h700e_firmware — cpe:2.3:o:netapp:h700e_firmware:-:*:*:*:*:*:*:*
netapp h410s_firmware — cpe:2.3:o:netapp:h410s_firmware:-:*:*:*:*:*:*:*
netapp h410c_firmware — cpe:2.3:o:netapp:h410c_firmware:-:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
oracle communications_cloud_native_core_binding_support_function 22.1.3 cpe:2.3:a:oracle:communications_cloud_native_core_binding_support_function:22.1.3:*:*:*:*:*:*:*
oracle communications_cloud_native_core_network_exposure_function 22.1.1 cpe:2.3:a:oracle:communications_cloud_native_core_network_exposure_function:22.1.1:*:*:*:*:*:*:*
oracle communications_cloud_native_core_policy 22.2.0 cpe:2.3:a:oracle:communications_cloud_native_core_policy:22.2.0:*:*:*:*:*:*:*

References for CVE-2021-3752

cvelogic Threat Intelligence