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Software Development KitApplication · Mediatek

CVE-2025-20734

MEDIUM · 5.3 CVSS v3.1 Published 2025-11-04
Fix available
A fix is available. Upgrade to after 7.6.7.2 or later.
See remediation →
55/100
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 wlan AP driver, there is a possible out of bounds write due to an incorrect bounds check. This could lead to local escalation of privilege if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: WCNCR00441507; Issue ID: MSV-4112.

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 bounds check error in the WLAN AP driver causes an out-of-bounds write vulnerability. An attacker with System-level privileges can exploit this to further escalate privileges locally. The vulnerability stems from incorrect validation of array indices or buffer boundaries in the driver's memory handling code.

MitigationApply the vendor patch (WCNCR00441507) to the WLAN AP driver. Since exploitation requires System-level access, treat this as a defense-in-depth measure for systems with compromised accounts.

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
Software Development KitApplication
Affected:<= 7.6.7.2
OpenwrtOperating system
Affected:= 19.07.0= 21.02.0

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

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

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 WLAN hardware in use
    Check system hardware info or network interfaces for Mediatek wireless adapters (e.g., via lspci, lsusb, or /proc/bus/pci)
    Affected if The system uses Mediatek wireless hardware and the WLAN AP driver is loaded
  2. Check Mediatek SDK version
    If using Mediatek SDK, locate and inspect the SDK version file or kernel module version (typically in /etc or embedded in driver module info)
    Affected if The SDK version is 7.6.7.2 or earlier
  3. Check OpenWrt version
    On OpenWrt systems, run 'cat /etc/openwrt_release' or 'opkg list-installed' to identify the installed version
    Affected if The installed OpenWrt version is 19.07.0 or 21.02.0
  4. Verify WLAN AP driver is loaded
    Check if the Mediatek WLAN AP driver kernel module is loaded (e.g., via lsmod, modinfo, or /proc/modules)
    Affected if The Mediatek WLAN AP driver module (e.g., mt76x2, mt7915, or similar) is present and active
  5. Confirm System-level access context
    Review system logs or audit records for any indication of compromised privileged accounts or unexpected processes running as root
    Affected if An attacker already has System-level access, they could exploit this vulnerability for privilege escalation

A user is affected if they run Mediatek WLAN AP driver on SDK <= 7.6.7.2 or OpenWrt 19.07.0/21.02.0 with the vulnerable driver enabled, and an attacker already has System-level privileges on the device.

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
Upgrade available Upgrade to a release after 7.6.7.2
Interim mitigation

Apply the vendor patch (WCNCR00441507) to the WLAN AP driver. Since exploitation requires System-level access, treat this as a defense-in-depth measure for systems with compromised accounts.

Recommended fix Moderate confidence

MediaTek SDK > 7.6.7.2 (verify patch WCNCR00441507 is included); OpenWRT updated versions beyond 19.07.0 and 21.02.0

  1. 1. Identify the MediaTek SDK version in use by checking the wlan AP driver package
  2. 2. Check MediaTek's official corp.mediatek.com for the WCNCR00441507 patch release notes to determine the fixed SDK version
  3. 3. For OpenWRT users: Check if OpenWRT 19.07.x and 21.02.x branches have released updated kernel/packages that include the MediaTek wlan driver patch
  4. 4. Upgrade the SDK to a version higher than 7.6.7.2 that incorporates patch WCNCR00441507
  5. 5. For OpenWRT: Apply available security updates or upgrade to a newer OpenWRT release that includes the fixed wlan driver
  6. 6. Verify the upgrade by checking the wlan driver version matches the patched release
Caveat SDK upgrades may require driver reconfiguration; OpenWRT upgrades may require configuration backup and restore

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

Fix this in Software Development Kit Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
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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-2025-20734 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