dbcve.org
AndroidOperating system · Google

CVE-2018-9393

MEDIUM · 6.7 CVSS v3.1 Published 2024-12-04
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 procfile_write of drivers/misc/mediatek/connectivity/wlan/gen2/os/linux/gl_proc.c, there is a possible OOB write 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 missing bounds check in the procfile_write function of MediaTek's WLAN driver (drivers/misc/mediatek/connectivity/wlan/gen2/os/linux/gl_proc.c) allows a local attacker to perform an out-of-bounds write, potentially achieving local privilege escalation to System level without user interaction.

MitigationApply a vendor patch that adds proper bounds validation in the procfile_write function to prevent OOB memory writes. This is a kernel driver issue requiring updated firmware or system-level patches from the device vendor.

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 the device chipset vendor
    Check /proc/cpuinfo or use 'getprop ro.hardware' or 'cat /sys/devices/soc0/soc_id' to determine if the device uses a MediaTek chipset
    Affected if The device does not use a MediaTek chipset, then the vulnerable driver is not present
  2. Confirm the MediaTek WLAN driver is present
    Check if the file /proc/mtk_wlan exists or if the MediaTek WLAN driver module is loaded using 'lsmod | grep mtk_wlan' or check /sys/kernel/debug/mtk_wlan
    Affected if The MediaTek WLAN driver is not loaded or the driver files are not present, then the attack surface does not exist
  3. Verify the Android version
    Run 'getprop ro.build.version.release' or check Settings > About Phone > Android version
    Affected if The device runs any version of Android with the vulnerable MediaTek driver, as all Android versions are affected according to the advisory
  4. Check for available security patches
    Check Settings > About Phone > Security patch level or run 'getprop ro.build.version.security_patch'
    Affected if The security patch level is earlier than the date when this CVE was fixed (June 2018 or later)

A user is affected if their Android device contains a MediaTek WLAN driver (MediaTek chipset) and has not received the vendor security patch that addresses the bounds check vulnerability in procfile_write.

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 a vendor patch that adds proper bounds validation in the procfile_write function to prevent OOB memory writes. This is a kernel driver issue requiring updated firmware or system-level patches from the device vendor.

Recommended fix Moderate confidence

Android Security Patch Level August 2018 or later

  1. Apply the Android security patch that includes the fix for CVE-2018-9393. This vulnerability was addressed in the Android Security Patch Level for August 2018 or later.
  2. Ensure your device receives regular Android security updates from your device manufacturer or carrier.
  3. If your device is no longer receiving official security updates, consider migrating to a device that still receives regular Android security patches.
  4. For custom ROM users, ensure you are using a kernel version that includes the MediaTek connectivity driver fix for the out-of-bounds write in procfile_write (drivers/misc/mediatek/connectivity/wlan/gen2/os/linux/gl_proc.c).
Caveat Devices that are no longer supported by manufacturers may not receive security updates; legacy devices may need to be replaced rather than patched

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

Fix this in Android Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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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-2018-9393 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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