CVE-2023-53827

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Last Modified: UTC

Moderate Moderate Impact What does this mean?
7.5 CVSS v3 Base Score

Description

The MITRE CVE dictionary describes this issue as

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix use-after-free in l2cap_disconnect_{req,rsp} Similar to commit d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put"), just use l2cap_chan_hold_unless_zero to prevent referencing a channel that is about to be destroyed.

Statement

A race in the L2CAP disconnect request/response handlers could access a channel that is being destroyed, causing a use-after-free and kernel crash. The fix uses l2cap_chan_hold_unless_zero() and proper locking around channel deletion to avoid referencing freed objects. An adjacent attacker over Bluetooth can trigger this during disconnect handling on an active link. Likely only denial-of-service kind of attack possible, but cannot prove this. The complexity of attack is high, because it requires a precise race condition between the local channel teardown (triggered by the kernel) and a crafted L2CAP_DisconnectReq or L2CAP_DisconnectRsp message sent by the remote peer at exactly the same time. The timing window is very narrow — the attacker must send or respond to the disconnect while the kernel is already in the process of releasing the l2cap_chan structure but before the reference count reaches zero. Achieving this reliably would require repeated connect/disconnect cycles or fuzzing at the signaling layer, making stable exploitation unlikely outside of a controlled test setup.

Additional Information

External References

Content from www.cve.org is not included.https://www.cve.org/CVERecord?id=CVE-2023-53827

Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2023-53827

Content from lore.kernel.org is not included.https://lore.kernel.org/linux-cve-announce/2025120952-CVE-2023-53827-b045@gregkh/T

Affected Packages and Issued Red Hat Security Errata

Products / Services Components State Errata
Red Hat Enterprise Linux 10 kernel Not affected
Red Hat Enterprise Linux 6 kernel Not affected
Red Hat Enterprise Linux 7 kernel Out of support scope
Red Hat Enterprise Linux 7 kernel-rt Out of support scope
Red Hat Enterprise Linux 8 kernel Affected
Red Hat Enterprise Linux 8 kernel-rt Affected
Red Hat Enterprise Linux 8.2 Advanced Update Support kernel Fixed RHSA-2026:3388
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support kernel Fixed RHSA-2026:3360
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On kernel Fixed RHSA-2026:3360
Red Hat Enterprise Linux 9 kernel Not affected
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authorities (CNA) source for its products and services (see Red Hat classifications ).

CVSS v3 Score Breakdown Red Hat NVD
CVSS v3 Base Score 7.5
Attack Vector Adjacent Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Impact High
Integrity Impact High
Availability Impact High

CVSS v3 Vector

Red Hat CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Frequently Asked Questions

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Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
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What can I do if my product is listed as "Fix deferred"?

 A deferred status means that a fix for an affected product version is not guaranteed due to higher-priority development work.

Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
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 The listed products were found to include one or more of the components that this vulnerability affects. These products underwent a thorough evaluation to determine their affectedness by this vulnerability. Note that layered products (such as container-based offerings) that consume affected components from any of the products listed in this table may be affected and are not represented.

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My product is listed as "Out of Support Scope". What does this mean?

 When a product is listed as "Out of Support Scope", it means a vulnerability with the impact level assigned to this CVE is no longer covered by its current support lifecycle phase. The product has been identified to contain the impacted component, but analysis to determine whether it is affected or not by this vulnerability was not performed. The product should be assumed to be affected. Customers are advised to apply any mitigation options documented on this page, consider removing or disabling the impacted component, or upgrade to a supported version of the product that has an update available.