ModemOperating system · Mediatek

CVE-2021-32486

HIGH · 7.5 CVSS v3.1 Published 2021-09-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges 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 modem 2G RRM, there is a possible system crash due to a heap buffer overflow. This could lead to remote denial of service with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY00500621; Issue ID: ALPS04964928.

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 heap buffer overflow vulnerability exists in the modem's 2G Radio Resource Management (RRM) component. This memory corruption issue can be triggered remotely, causing system crash and leading to complete denial of service. No user interaction or elevated privileges are required for exploitation.

MitigationApply vendor patch MOLY00500621 to update the modem firmware and fix the heap buffer overflow in the 2G RRM component.

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
ModemOperating system
Affected:= lr12a= lr13

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

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 modem in use
    Check system information or modem diagnostics to confirm the device uses a Mediatek modem chipset
    Affected if The system does not use a Mediatek modem chipset (not lr12a or lr13)
  2. Check modem model version
    Query modem firmware information to determine if the model is lr12a or lr13
    Affected if Modem model is lr12a or lr13 and firmware has not been updated
  3. Verify 2G/RRM component is enabled
    Check modem radio configuration settings to confirm 2G (GSM) network support or RRM functionality is active
    Affected if 2G support and RRM component are disabled in the modem configuration
  4. Check current modem firmware patch level
    Query the installed modem firmware version and compare against the vendor patch MOLY00500621
    Affected if Modem firmware is older than the patched version MOLY00500621 or the patch has not been applied
  5. Confirm exploitability via network access
    Verify the modem is accessible over the mobile network and can receive radio resource management messages
    Affected if Modem is reachable and 2G RRM processing is active without the vendor patch applied

User is affected if their device contains a Mediatek lr12a or lr13 modem with 2G RRM enabled and firmware versions prior to the MOLY00500621 patch.

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 vendor patch MOLY00500621 to update the modem firmware and fix the heap buffer overflow in the 2G RRM component.

Fix this in Modem Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing8.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,760
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Scan for this in your stack

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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-2021-32486 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
  • No spam, self-promotion, credentials, or personal data