Local root escalation via premature Binder cleanup
Published Feb 28, 2023 · Updated Aug 2, 2024
Use-after-free in the Binder kernel driver in Google Android allows local users to gain root privileges through a crafted Binder transaction. An unaligned offsets_size reaches an error path where binder_transaction_buffer_release cleans up unprocessed Binder nodes and decrements their reference counts. An untrusted app needs no user interaction; freeing a still-referenced binder_node leaves a dangling pointer that supports kernel memory reuse and privilege escalation.
Summary
What happened
Use-after-free in the Binder kernel driver in Google Android allows local users to gain root privileges through a crafted Binder transaction. An unaligned offsets_size reaches an error path where binder_transaction_buffer_release cleans up unprocessed Binder nodes and decrements their reference counts. An untrusted app needs no user interaction; freeing a still-referenced binder_node leaves a dangling pointer that supports kernel memory reuse and privilege escalation.
The record
- CVE
- CVE-2023-20938
- Published
- Feb 28, 2023
- Updated
- Aug 2, 2024
- Vendor
- Google Cloud
- Product
- Android
- Classifications
- CWE-416, T1404
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 28, 2023CVE publishedPublication date reported by the CVE source.
- Aug 2, 2024Record 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?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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.
Public exploit references
- Attacking Android Binder privilege-escalation exploitfunctional · validated
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Technologies
Your stack
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Your stack
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