Enterprise LinuxOperating system · Redhat
CVE-2020-25661
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 · uneditedA Red Hat only CVE-2020-12351 regression issue was found in the way the Linux kernel's Bluetooth implementation handled L2CAP packets with A2MP CID. This flaw allows a remote attacker in an adjacent range to crash the system, causing a denial of service or potentially executing arbitrary code on the system by sending a specially crafted L2CAP packet. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
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 confidenceA vulnerability in the Linux kernel's Bluetooth stack allows remote attackers within adjacent range to send specially crafted L2CAP packets with A2MP CID, potentially causing a denial of service (system crash) or arbitrary code execution. This is a regression of CVE-2020-12351, affecting the A2MP protocol handling in the kernel's Bluetooth implementation.
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
Enterprise LinuxOperating system
= 8.3CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:A/AC:L/PR:N/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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Confirm operating system versionRun 'cat /etc/redhat-release' or 'hostnamectl' to verify the installed OS is Red Hat Enterprise Linux version 8.3Affected if The system is running RHEL 8.3 specifically (not another version)
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Check kernel versionRun 'uname -r' to retrieve the running kernel version and compare it against the kernel versions shipped with RHEL 8.3 that contain the vulnerabilityAffected if The kernel version matches the vulnerable kernel shipped with RHEL 8.3
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Verify Bluetooth is enabledRun 'systemctl status bluetooth' to check if the Bluetooth service is active, or run 'rfkill list' to see if Bluetooth is unblockedAffected if Bluetooth is enabled and the Bluetooth service is running
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Check for vulnerable Bluetooth modulesRun 'lsmod | grep bluetooth' to list loaded Bluetooth kernel modules such as bluetooth, l2cap, and a2mpAffected if The bluetooth and related L2CAP/A2MP modules are loaded into the kernel
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Confirm A2MP protocol supportInspect /proc/bluetooth/l2cap or use 'hciconfig -a' to check if the system has Bluetooth adapters configured with L2CAP/A2MP protocol support enabledAffected if L2CAP with A2MP CID handling is available on a configured Bluetooth adapter
The system is vulnerable if it is RHEL 8.3 with a vulnerable kernel version AND has Bluetooth enabled with the affected L2CAP/A2MP modules loaded and active.
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 kernel security updates or patches addressing this regression. If immediate patching is not feasible, disable Bluetooth or limit exposure by using non-discoverable mode and restricting physical proximity access.
Fix this in Enterprise Linux
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing5.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,752.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-25661 — 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-2020-25661 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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