AndroidOperating system · Google

CVE-2023-21058

CRITICAL · 9.8 CVSS v3.1 Published 2023-03-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In lcsm_SendRrAcquiAssist of lcsm_bcm_assist.c, there is a possible out of bounds write due to a missing bounds check. This could lead to remote code execution with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-246169606References: N/A

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A missing bounds check in the lcsm_SendRrAcquiAssist function in lcsm_bcm_assist.c allows an out-of-bounds write vulnerability in the Android kernel. This memory corruption flaw can be exploited for remote code execution without requiring user interaction or additional privileges.

MitigationApply the Android kernel security patch for Android ID A-246169606 which adds proper bounds validation in the lcsm_SendRrAcquiAssist function to prevent the out-of-bounds write.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
AndroidOperating system
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Android kernel version
    Run 'cat /proc/version' or check 'Settings > About Phone > Kernel Version' to identify your kernel build
    Affected if Kernel version is older than the March 2023 Android security patch level (or if you cannot confirm the A-246169606 patch was applied)
  2. Verify lcsm_bcm_assist module presence
    Check if the lcsm_bcm_assist module exists in your kernel by searching /proc/kallsyms or examining /lib/modules/ for any bcm_assist related kernel modules
    Affected if The lcsm_bcm_assist component is loaded in your kernel (this indicates the vulnerable code path exists)
  3. Confirm Android security patch level
    Go to Settings > About Phone > Build Number (tap repeatedly to enable developer options) then check Settings > System > Developer Options > Security Patch Level
    Affected if The Security Patch Level is earlier than March 2023, indicating the bounds check fix has not been applied

If your Android device runs a kernel version predating the March 2023 Android security patch and contains the lcsm_bcm_assist component, you are likely affected by this out-of-bounds write vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the Android kernel security patch for Android ID A-246169606 which adds proper bounds validation in the lcsm_SendRrAcquiAssist function to prevent the out-of-bounds write.

Recommended fix Moderate confidence

Latest Android OS version with current monthly security patch (check Android Security Bulletin for specific release containing A-246169606 fix)

  1. 1. Navigate to Settings > System > Security Update on the Android device
  2. 2. Check for and install the latest Android security patch update
  3. 3. Verify the installed security patch level includes the fix for A-246169606
  4. 4. If available, upgrade to the latest Android OS version to ensure kernel-level fixes are included
Caveat Major Android OS upgrades may cause app compatibility issues; backup data before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Android Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing8.0 h
  • Review / QA4.0 h
24.0 hours of engineering $4,160
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Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-21058 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data