CVE-2021-3743

Exp

An out-of-bounds (OOB) memory read flaw was found in the Qualcomm IPC router protocol in the Linux kernel. A missing sanity check allows a local attacker to gain access to out-of-bounds memory, leading to a system crash or a leak of internal kernel information. The highest threat from this vulnerability is to system availability.

Published: 2022-03-04 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3743 is rated High Exploit Risk (61.3/100): CVSS High severity, with low exploitation likelihood (EPSS 0.73%). 2 public exploit reference(s) are indexed (Exploit-DB). 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-2021-3743

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

Exploit prediction scoring system (EPSS) score for CVE-2021-3743

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 0.01% 0.73% +0.71%
2 2025-11-21 0.06% 0.01% -0.05%
3 2025-11-18 — 0.06% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3743

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.1 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
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:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.2 [email protected]
3.6 2.0 LOW
AV:L/AC:L/Au:N/C:P/I:N/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 3.9 4.9 [email protected]

Weakness enumeration for CVE-2021-3743

OS Trackers for CVE-2021-3743

vendor priority summary link
debian not yet assigned CVE-2021-3743 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-2021-3743
redhat medium — https://access.redhat.com/security/cve/CVE-2021-3743
suse medium — https://www.suse.com/security/cve/CVE-2021-3743/
ubuntu medium CVE-2021-3743 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, not-affected 216, released 211, ignored 49. https://ubuntu.com/security/CVE-2021-3743

Affected software / configurations for CVE-2021-3743

Vendor Product Version Raw CPE
linux linux_kernel > 5.14.1, < 5.17 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 5.14 cpe:2.3:o:linux:linux_kernel:5.14:rc6:*:*:*:*:*:*
linux linux_kernel 5.17 cpe:2.3:o:linux:linux_kernel:5.17:-:*:*:*:*:*:*
linux linux_kernel 5.17 cpe:2.3:o:linux:linux_kernel:5.17:rc1:*:*:*:*:*:*
linux linux_kernel 5.17 cpe:2.3:o:linux:linux_kernel:5.17:rc2:*:*:*:*:*:*
linux linux_kernel 5.17 cpe:2.3:o:linux:linux_kernel:5.17:rc3:*:*:*:*:*:*
linux linux_kernel 5.17 cpe:2.3:o:linux:linux_kernel:5.17:rc4:*:*:*:*:*:*
linux linux_kernel 5.17 cpe:2.3:o:linux:linux_kernel:5.17:rc5:*:*:*:*:*:*
linux linux_kernel 5.17 cpe:2.3:o:linux:linux_kernel:5.17:rc6:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
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:-:*:*:*:*:*:*:*
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-2021-3743

URL Tags
https://bugzilla.redhat.com/show_bug.cgi?id=1997961 Issue Tracking Patch Third Party Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=7e78c597c3eb Patch Vendor Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7e78c597c3ebfd0cb329aa09a838734147e4f117 Patch Vendor Advisory
https://github.com/torvalds/linux/commit/7e78c597c3ebfd0cb329aa09a838734147e4f117 Patch Third Party Advisory
https://lists.openwall.net/netdev/2021/08/17/124 Exploit Mailing List Third Party Advisory
https://security.netapp.com/advisory/ntap-20220407-0007/ Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/08/27/2 Exploit Mailing List Patch Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.html Patch Third Party Advisory
cvelogic Threat Intelligence