Ubuntu LinuxOperating system · Canonical
CVE-2019-19344
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 · uneditedThere is a use-after-free issue in all samba 4.9.x versions before 4.9.18, all samba 4.10.x versions before 4.10.12 and all samba 4.11.x versions before 4.11.5, essentially due to a call to realloc() while other local variables still point at the original buffer.
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 use-after-free vulnerability exists in Samba versions 4.9.x before 4.9.18, 4.10.x before 4.10.12, and 4.11.x before 4.11.5. The flaw occurs when realloc() is called to resize a memory buffer, but other local variables continue to reference the original buffer address. After realloc() potentially moves the buffer to a new memory location, these stale pointers are dereferenced, leading to use-after-free conditions that could cause crashes or potentially enable arbitrary code execution.
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
Ubuntu LinuxOperating system
= 16.04= 18.04= 19.04= 19.10>= 4.9.0, < 4.9.18>= 4.10.0, < 4.10.12>= 4.11.0, < 4.11.5all versions= 1.2all versions= 6.2= 15.1CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/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 checksWork through these to decide whether this CVE applies to you.
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Check Samba installation statusRun 'smbd --version' or 'samba --version' to determine if Samba is installed and retrieve its version numberAffected if Samba is installed with a version between 4.9.0 and 4.9.17, between 4.10.0 and 4.10.11, or between 4.11.0 and 4.11.4
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Verify package manager versionOn Debian/Ubuntu systems, run 'dpkg -l | grep samba' or 'apt show samba'; on RHEL/CentOS run 'rpm -qa | grep samba'; on SUSE run 'rpm -qa | grep samba'Affected if The installed Samba package version falls within the affected ranges listed above
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Check Synology-specific Samba versionIf running on a Synology device, access the control panel and check the installed version of 'Directory Server' or 'Diskstation Manager' that includes Samba functionalityAffected if Any version of Synology Directory Server, Skynas, Diskstation Manager 6.2, or Router Manager 1.2 is in use, as these include the vulnerable Samba code
Your environment is affected if Samba (whether standalone or embedded in Synology, Ubuntu, or openSUSE products) is installed with version 4.9.x before 4.9.18, 4.10.x before 4.10.12, or 4.11.x before 4.11.5.
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 data4.9.184.10.124.11.5
Upgrade Samba to version 4.9.18 or later, 4.10.12 or later, or 4.11.5 or later. Alternatively, apply the vendor-provided security patches to address the improper realloc() handling.
Fix this in Ubuntu Linux
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing12.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,616.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-19344 — 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-2019-19344 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
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