CVE-2025-20736
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 · uneditedIn 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: WCNCR00435347; Issue ID: MSV-4049.
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 · moderate confidenceIn the WLAN AP driver, an out-of-bounds write vulnerability exists due to an incorrect bounds check. This allows a local attacker who already has System privilege to escalate privileges further. The issue is in the driver's memory handling where boundary validation is flawed.
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<= 7.6.7.2= 19.07.0= 21.02.0CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify the Mediatek SDK or Openwrt versionFor Mediatek SDK, run: cat /etc/version or check system info files in /etc or /opt. For Openwrt, run: cat /etc/os-release or cat /etc/openwrt_versionAffected if The version is <= 7.6.7.2 for Mediatek SDK, or exactly 19.07.0 or 21.02.0 for Openwrt
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Verify the WLAN AP driver is loadedRun: lsmod | grep -i wifi or iwconfig to list wireless interfaces. Check /proc/modules for mediatek wlan driver modulesAffected if A WLAN driver module is loaded and active (the driver must be present for the vulnerability to be exploitable)
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Confirm wireless AP/Access Point functionality is configuredRun: wifi status or iw dev to list configured wireless interfaces in AP mode. Check /etc/config/wireless for Openwrt configurationsAffected if An Access Point interface is actively configured or running (the vulnerable code path executes when AP mode is enabled)
You are affected if your Mediatek SDK version is <= 7.6.7.2 OR your Openwrt version is 19.07.0 or 21.02.0, AND the WLAN AP driver is loaded with an AP interface actively configured.
Generated from the published advisory. Verify against your own configuration.
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 dataApply patch WCNCR00435347 to correct the bounds check logic in the WLAN AP driver. Since this requires System privilege to exploit, ensure strict access controls on systems hosting this driver.
- Consultation3.0 h
- Implementation6.0 h
- Testing5.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-20736 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-20736 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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