CVE-2023-53374 [High] | Use-After-Free in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_conn: fail SCO/ISO via hci_conn_failed if ACL gone early Not calling hci_(dis)connect_cfm before deleting conn referred to by a socket generally results to use-after-free. When cleaning up SCO connections when the parent ACL is deleted too early, use hci_conn_failed to do the connection cleanup properly. We also need to clean up ISO connections in a similar situation when connecting has started but LE Create CIS is not yet sent, so do it too here.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-09-19	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-09-19

—

0.02%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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: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.	1.8	5.9	[email protected]
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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: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.	1.8	5.9	134c704f-9b21-4f2e-91b3-4a467353bcc0

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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: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.

1.8

5.9

[email protected]

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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: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.

1.8

5.9

134c704f-9b21-4f2e-91b3-4a467353bcc0

OS Trackers for CVE-2023-53374

vendor	priority	summary	link
`debian`	unimportant	CVE-2023-53374 unimportant 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-2023-53374
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2023-53374
`suse`	medium	CVE-2023-53374 severity moderate: SUSE including 402 source package names (2.1.3-6.80:kernel-default-base-6.4.0-35.1.21.12, 2.1.3-7.57:kernel-default-6.4.0-35.1, …), 868 product×package rows across 182 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (182 product lines)): Fixed 442, Known Affected 231, Known Not Affected 195.	https://www.suse.com/security/cve/CVE-2023-53374/
`ubuntu`	medium	CVE-2023-53374 medium priority: Ubuntu including 150 source packages (linux, linux-allwinner-5.19, …), 1350 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 969, ignored 159, not-affected 142, released 80.	https://ubuntu.com/security/CVE-2023-53374

Affected software / configurations for CVE-2023-53374

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 6.3.8, < 6.4	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.4.1, < 6.4.16	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.5, < 6.5.3	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	6.4	cpe:2.3:o:linux:linux_kernel:6.4:-::::::
linux	linux_kernel	6.4	cpe:2.3:o:linux:linux_kernel:6.4:rc4::::::
linux	linux_kernel	6.4	cpe:2.3:o:linux:linux_kernel:6.4:rc5::::::
linux	linux_kernel	6.4	cpe:2.3:o:linux:linux_kernel:6.4:rc6::::::
linux	linux_kernel	6.4	cpe:2.3:o:linux:linux_kernel:6.4:rc7::::::

References for CVE-2023-53374

URL	Tags
https://git.kernel.org/stable/c/3344d318337d9dca928fd448e966557ec5063f85	Patch
https://git.kernel.org/stable/c/397d58007532644b35fad746da48c41161f32a57	Patch
https://git.kernel.org/stable/c/e94b898463a62b72a2a8b75dea8936bf4db78e00	Patch

URL

CVE-2023-53374 | Bluetooth: hci_conn: fail SCO/ISO via hci_conn_failed if ACL gone early

Exploit prediction scoring system (EPSS) score for CVE-2023-53374

Common vulnerability scoring system (CVSS) metrics for CVE-2023-53374

Weakness enumeration for CVE-2023-53374

OS Trackers for CVE-2023-53374

Affected software / configurations for CVE-2023-53374

References for CVE-2023-53374