Local privilege escalation via zero channel underflow
Published Jul 14, 2021 · Updated Aug 3, 2024
Out-of-bounds write in Android 8.1 through 11 allows local users to escalate privileges through the Bluetooth server-channel allocator. Passing server channel zero defeats the lower-bound check, so BTM_TryAllocateSCN indexes btm_scn at scn minus one and writes before the array. User-level code is required, but exploitation needs no user interaction and can execute with elevated privileges.
Summary
What happened
Out-of-bounds write in Android 8.1 through 11 allows local users to escalate privileges through the Bluetooth server-channel allocator. Passing server channel zero defeats the lower-bound check, so BTM_TryAllocateSCN indexes btm_scn at scn minus one and writes before the array. User-level code is required, but exploitation needs no user interaction and can execute with elevated privileges.
The record
- CVE
- CVE-2021-0589
- Published
- Jul 14, 2021
- Updated
- Aug 3, 2024
- Vendor
- Google Cloud
- Product
- Android
- Classifications
- CWE-787, T1404
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 14, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=Android-11 Android-8.1 Android-9 Android-10
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
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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