AndroidOperating system · Google

CVE-2018-9386

MEDIUM · 6.7 CVSS v3.1 Published 2024-12-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
69/100
Remediation priority · Elevated
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 reboot_block_command of htc reboot_block driver, there is a possible stack buffer overflow due to a missing bounds check. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.

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 stack buffer overflow exists in the reboot_block_command function of the HTC reboot_block kernel driver due to a missing bounds check on user-supplied input. This allows a local attacker with System execution privileges to potentially escalate privileges. The vulnerability does not require user interaction.

MitigationApply a bounds check to the input buffer in the reboot_block_command function within the HTC reboot_block driver, then rebuild and deploy the patched kernel/driver.

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
Local
Complexity
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:H/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. Identify device manufacturer
    Check if the device is from HTC by running 'getprop ro.product.manufacturer' or 'getprop ro.build.manufacturer' in a terminal or ADB shell
    Affected if Device is not HTC hardware - the HTC reboot_block driver is vendor-specific and unlikely to be present on non-HTC devices
  2. Verify reboot_block driver presence
    Check for the existence of the reboot_block driver by examining /proc/modules, /sys/module/, or searching for 'reboot_block' in /proc/kallsyms if available
    Affected if The reboot_block module or symbol is not found in the kernel - the vulnerable driver is not present
  3. Confirm driver is loaded or built-in
    Run 'lsmod' to check if reboot_block is loaded as a module, or check kernel config for built-in driver status
    Affected if The driver is neither loaded nor compiled as built-in - the attack surface does not exist
  4. Check for System privileges context
    Determine if the detection is running in a context with System-level privileges (UID 1000) using 'id' command or checking /proc/self/status for Uid
    Affected if Exploitation requires System execution privileges (UID 1000) - lower privilege levels cannot directly trigger this vulnerability
  5. Confirm Android version
    Run 'getprop ro.build.version.release' to identify the Android version
    Affected if All Android versions are affected per the CVE, but confirming version helps with scoping and remediation tracking

Device is affected if it is HTC hardware with the reboot_block kernel driver present or loaded, and the attacker has System-level execution privileges.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply a bounds check to the input buffer in the reboot_block_command function within the HTC reboot_block driver, then rebuild and deploy the patched kernel/driver.

Fix this in Android Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing4.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,540
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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-2018-9386 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
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