Reachable AssertionWeakness · CWE-617

CVE-2024-7138

MEDIUM · 6.5 CVSS v3.1 Published 2024-12-19
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
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
An assert may be triggered, causing a temporary denial of service when a peer device sends a specially crafted malformed L2CAP packet. If a watchdog timer is not enabled, a hard reset is required to recover the device.

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 malformed L2CAP packet from a peer device can trigger an assertion failure in the Bluetooth stack, causing a temporary denial of service. The device requires a hard reset to recover if a watchdog timer is not enabled.

MitigationEnable the watchdog timer to allow automatic recovery from assert conditions, or implement proper input validation on incoming L2CAP packets to prevent the assert from being triggered by malformed data.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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

CVSS:3.1/AV:A/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. Verify Bluetooth is enabled
    Check system Bluetooth status via OS settings, hcitool dev, or bluetoothctl show. On Linux: hciconfig -a or systemctl status bluetooth
    Affected if Bluetooth is active and the system processes incoming Bluetooth connections
  2. Confirm L2CAP protocol support is active
    Check if L2CAP channels can be established. On Linux: btmon -w /tmp/btmon.log & then attempt l2ping or check /proc/bluetooth/*/l2cap for active channels. Alternatively, check Bluetooth stack logs for L2CAP channel handler initialization
    Affected if L2CAP protocol handling is enabled in the Bluetooth stack configuration
  3. Identify the Bluetooth stack version
    Run bluetoothd --version, or check package manager: dpkg -l | grep bluez, rpm -qa | grep bluez, or cat /usr/lib/systemd/system/bluetooth.service.d/*.conf for version info. On Android: Settings > About Phone > Bluetooth MAC address tap for stack version
    Affected if The installed Bluetooth stack version falls within any known vulnerable version range for this CVE (compare your version to the affected ranges)
  4. Check watchdog timer status
    On Linux: cat /sys/class/watchdog/*/state or ps aux | grep watchdog. Check kernel config: zcat /proc/config.gz | grep CONFIG_WATCHDOG or check /etc/default/watchdog. On embedded systems: examine device tree or bootloader config for watchdog enablement
    Affected if Watchdog timer is disabled, meaning the system cannot automatically recover from the assert condition without manual intervention
  5. Assess exposure to untrusted Bluetooth devices
    Review if the system accepts L2CAP connections from unpaired/untrusted devices. Check Bluetooth adapter discoverability mode: hciconfig or bluetoothctl show. Review firewall rules for Bluetooth: iptables -L -n | grep -i bluetooth
    Affected if The system accepts connections from untrusted or unknown Bluetooth devices, making it reachable to malformed L2CAP packets

A system is affected if it has an active Bluetooth stack with L2CAP enabled, runs a vulnerable version, and can receive L2CAP packets from untrusted devices without watchdog protection to auto-recover.

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

Enable the watchdog timer to allow automatic recovery from assert conditions, or implement proper input validation on incoming L2CAP packets to prevent the assert from being triggered by malformed data.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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Scan for this in your stack

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dbcve dependency scanner

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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-2024-7138 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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  • Version or environment caveats, and links to real fixes
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