Linux KernelOperating system · Linux
CVE-2023-39180
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 flaw was found within the handling of SMB2_READ commands in the kernel ksmbd module. The issue results from not releasing memory after its effective lifetime. An attacker can leverage this to create a denial-of-service condition on affected installations of Linux. Authentication is not required to exploit this vulnerability, but only systems with ksmbd enabled are vulnerable.
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 confidenceA memory leak vulnerability exists in the Linux kernel's ksmbd SMB server module when handling SMB2_READ commands. The flaw causes memory to not be released after its effective lifetime, leading to resource exhaustion and potential denial-of-service. Attackers can exploit this without authentication on systems where ksmbd is enabled.
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
Linux KernelOperating system
all versionsCVSS 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 checksWork through these to decide whether this CVE applies to you.
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Verify if ksmbd module is loadedRun `lsmod | grep ksmbd` or check `/proc/modules` for the ksmbd entryAffected if The ksmbd module appears in the loaded modules list
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Confirm if ksmbd service is activeRun `systemctl status ksmbd` or check for ksmbd-related processes with `ps aux | grep ksmbd`Affected if The ksmbd service is running or ksmbd processes are visible
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Check if SMB shares are being servedReview active SMB configurations in `/etc/ksmbd/` or check for listening port 445 with `ss -tlnp | grep 445`Affected if Port 445 is listening or SMB share configurations exist for ksmbd
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Identify kernel versionRun `uname -r` to display the running kernel versionAffected if The system is running any Linux kernel version (all versions are affected per CVE description)
The environment is affected if the ksmbd module is loaded and the ksmbd SMB service is actively serving connections, regardless of kernel version since all versions are impacted.
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 dataDisable the ksmbd module if SMB service is not required, or apply kernel security updates/patches when available to address the memory management flaw in SMB2_READ command handling.
Fix this in Linux Kernel
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-39180 — 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-2023-39180 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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- 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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