Local privilege escalation via L2CAP reference race
Published Dec 16, 2022 · Updated Apr 21, 2025
Use-after-free in Android kernel Bluetooth L2CAP allows local users to elevate privileges on affected devices without user interaction. The channel lookup path can increment a zero reference after sock_close drops the final reference but before hci_rx_work destroys the channel. Low-privileged local access is required; successful exploitation executes code with elevated kernel privileges, while failed attempts can crash the device.
Summary
What happened
Use-after-free in Android kernel Bluetooth L2CAP allows local users to elevate privileges on affected devices without user interaction. The channel lookup path can increment a zero reference after sock_close drops the final reference but before hci_rx_work destroys the channel. Low-privileged local access is required; successful exploitation executes code with elevated kernel privileges, while failed attempts can crash the device.
The record
- CVE
- CVE-2022-20566
- Published
- Dec 16, 2022
- Updated
- Apr 21, 2025
- Vendor
- Google Cloud
- Product
- Android
- Classifications
- CWE-667, CWE-416, T1404
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 16, 2022CVE publishedPublication date reported by the CVE source.
- Apr 21, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=Android kernel
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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