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AndroidOperating system · Google

CVE-2018-9395

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 mtk_cfg80211_vendor_packet_keep_alive_start and mtk_cfg80211_vendor_set_config of drivers/misc/mediatek/connectivity/wlan/gen2/os/linux/gl_vendor.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

Out-of-bounds write vulnerability in MediaTek's WiFi driver (mtk_cfg80211_vendor_packet_keep_alive_start and mtk_cfg80211_vendor_set_config functions in gl_vendor.c) due to missing bounds check on user-supplied data, allowing local privilege escalation to System level.

MitigationApply the MediaTek vendor patch which adds proper bounds validation before writing data in the affected vendor command handlers.

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 MediaTek WiFi chipset
    Check the device's WiFi chipset by reviewing kernel boot logs or using 'ls /sys/class/net/wlan0/device/' to examine the device path, or use 'getprop ro.wifi.driver' if available
    Affected if The device uses a MediaTek (MediaTek Inc.) WiFi chipset rather than Broadcom, Qualcomm, or other vendors
  2. Locate the vulnerable driver file
    Search for the MediaTek vendor driver file: 'find /system/lib -name "libmediatek_cfg80211.so" -o -name "mtk_cfg80211*"' or check kernel modules for 'mediatek' WiFi driver
    Affected if The MediaTek WiFi vendor driver library (libmediatek_cfg80211.so) is present on the device
  3. Verify vulnerable functions exist
    Use 'strings' or a disassembler tool on the driver library to search for 'mtk_cfg80211_vendor_packet_keep_alive_start' and 'mtk_cfg80211_vendor_set_config' function symbols
    Affected if These specific vendor command handler functions are present in the driver binary, indicating the affected code path exists
  4. Check vendor command interface exposure
    Examine if the WiFi vendor command interface is enabled by checking CONFIG_CFG80211_VENDOR_CMD_EXTENSION or similar kernel config, and verify vendor HAL is exposed via 'getprop | grep vendor.hal'
    Affected if The MediaTek vendor command extension interface is enabled and accessible to privileged system components
  5. Confirm System-level WiFi privileges
    Check if any application holds the 'android.permission.MAINLINE_NETWORK_STACK' or system-level WiFi permissions by examining running processes with 'ps -A | grep wifi' and checking UID/groups
    Affected if The device runs processes or services at System UID (uid=1000) that can invoke the vulnerable vendor commands through the WiFi driver interface

The device is affected if it uses a MediaTek WiFi chipset with the vulnerable vendor driver containing mtk_cfg80211_vendor_packet_keep_alive_start or mtk_cfg80211_vendor_set_config functions, where the vendor command interface is accessible to privileged callers.

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 MediaTek vendor patch which adds proper bounds validation before writing data in the affected vendor command handlers.

Recommended fix Moderate confidence

Android devices receiving July 2018 Security Patch Level or later; specific MediaTek connectivity driver update (mtk_cfg80211) with bounds checking added to mtk_cfg80211_vendor_packet_keep_alive_start and mtk_cfg80211_vendor_set_config functions

  1. Check your Android device's current security patch level in Settings > About Phone > Security Patch Level
  2. Verify if your device manufacturer has released a security update that includes the fix for CVE-2018-9395
  3. If an update is available, backup your device data
  4. Apply the security update through Settings > System > Software Update or your manufacturer's update mechanism
  5. After updating, confirm the security patch level includes the month the fix was released (CVE-2018-9395 was addressed in the July 2018 Android Security Patch Level or later)
Caveat Some older devices may no longer receive security updates; ensure device is still supported by manufacturer before upgrading

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
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,560
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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-2018-9395 in production — separate from our analysis above.

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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