Nr15Operating system · Mediatek

CVE-2025-20755

MEDIUM · 5.3 CVSS v3.1 Published 2025-12-02
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
59/100
Remediation priority · Elevated
Remotely reachable 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, there is a possible application crash due to improper input validation. This could lead to remote denial of service, if a UE has connected to a rogue base station controlled by the attacker, with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY00628396; Issue ID: MSV-4775.

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 confidence

A denial of service vulnerability exists in cellular modem firmware where improper input validation allows a remote attacker to crash the modem by transmitting specially crafted signals from a rogue base station. When a User Equipment connects to the attacker's malicious cell tower, malformed network messages trigger an application crash in the modem component, causing a denial of service condition.

MitigationApply the vendor patch (MOLY00628396) to the modem firmware. Until the patch is deployed, advise users to avoid connecting to untrusted or unknown cellular base stations to reduce exposure to this attack vector.

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
Nr15Operating 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
Network
Complexity
High
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:H/PR:L/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. Confirm Mediatek Nr15 modem is present
    Identify if the device or system contains a Mediatek Nr15 cellular modem component. This may be documented in device specifications, system inventory, or modem diagnostic outputs (e.g., AT+CGMM or AT+CGMI commands).
    Affected if The device does not contain a Mediatek Nr15 modem - this CVE does not apply.
  2. Check installed modem firmware version
    Retrieve the current modem firmware version using vendor-specific diagnostic commands (such as AT+CGMR, AT+CVERSION, or through manufacturer utility tools). Compare the version string against the patch level MOLY00628396.
    Affected if The firmware version is below MOLY00628396 or cannot be verified, indicating the vulnerability is present.
  3. Verify cellular network connectivity is enabled
    Confirm that the modem's radio and network registration functions are active. Check modem status via AT+CREG?, AT+CGREG?, or similar network registration queries, or review system network configuration.
    Affected if Cellular connectivity is enabled and the modem can register on networks - the attack surface exists.
  4. Assess exposure to untrusted base stations
    Review whether the device configuration permits connection to any available cellular network, or if it is restricted to trusted operators via SIM lock, preferred network lists, or operator policies.
    Affected if The device can connect to untrusted or unknown cellular base stations (rogue cell towers), exposing it to the attack vector.

A device is affected if it contains a Mediatek Nr15 modem with firmware version below MOLY00628396 and has cellular network connectivity enabled that allows connection to untrusted base stations.

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 the vendor patch (MOLY00628396) to the modem firmware. Until the patch is deployed, advise users to avoid connecting to untrusted or unknown cellular base stations to reduce exposure to this attack vector.

Fix this in Nr15 Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,760
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-20755 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-20755 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
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