315 5g Iot Modem FirmwareOperating system · Qualcomm

CVE-2023-33042

HIGH · 7.5 CVSS v3.1 Published 2023-12-05
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
Transient DOS in Modem after RRC Setup message is received.

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 transient denial of service vulnerability exists in the modem's RRC (Radio Resource Control) message handling logic. When a specific RRC Setup message is received, it causes the modem to become unresponsive, likely due to a crash or hang in the radio protocol stack processing.

MitigationApply vendor firmware updates when available; until then, monitor modem availability and implement network-level protections to limit exposure to unauthenticated RRC messages.

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
315 5g Iot Modem FirmwareOperating system
Affected:all versions
Ar8035 FirmwareOperating system
Affected:all versions
Wcn3991 FirmwareOperating system
Affected:all versions
Wcn3998 FirmwareOperating system
Affected:all versions
Wcn6750 FirmwareOperating system
Affected:all versions
Qca6390 FirmwareOperating system
Affected:all versions
Wcn685x 5 FirmwareOperating system
Affected:all versions
Wcn685x 1 FirmwareOperating 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
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 installed Qualcomm modem hardware
    Use system commands such as 'lspci -v', 'lsusb', or check /dev/ttyUSB* entries to list modem devices. Look for identifiers matching the affected chips: Qualcomm 315 5G IoT, Ar8035, Wcn3991, Wcn3998, Wcn6750, Qca6390, Wcn685x 5, or Wcn685x 1.
    Affected if Any of these Qualcomm modem chips are present in the system
  2. Check modem firmware version
    Query the modem firmware version via AT commands (e.g., 'AT+GMR' or 'AT+CGMR') through a serial interface, or use manufacturer-provided tools such as 'qdmactl' or 'quectel-cm' for Qualcomm-based modems.
    Affected if The firmware version cannot be determined or is older than available vendor patches (all versions listed are affected)
  3. Verify cellular radio interface is active
    Check if the modem's radio interface is enabled using commands like 'ifconfig', 'ip link', or 'nmcli device status' to see if cellular interfaces (such as wwan0, rmnet0) are present and up.
    Affected if A cellular interface is present and active, meaning the RRC message handling pathway is exposed
  4. Confirm RRC protocol stack is operational
    Monitor modem logs or status via vendor tools (e.g., 'diag_mdlog', 'qlog') or check /var/log/messages for modem-related radio events. RRC is a core LTE/5G protocol and is enabled by default on active modems.
    Affected if The modem shows active cellular registration or connection events, indicating RRC stack is running

If the environment contains any of the listed Qualcomm modem chips and has an active cellular connection, the system is likely affected by this RRC DoS vulnerability.

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 firmware updates when available; until then, monitor modem availability and implement network-level protections to limit exposure to unauthenticated RRC messages.

Fix this in 315 5g Iot Modem Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
32.0 hours of engineering $5,600
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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-2023-33042 in production — separate from our analysis above.

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What this is

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What belongs here
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