Debian LinuxOperating system · Debian
CVE-2017-13723
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 · uneditedIn X.Org Server (aka xserver and xorg-server) before 1.19.4, a local attacker authenticated to the X server could overflow a global buffer, causing crashes of the X server or potentially other problems by injecting large or malformed XKB related atoms and accessing them via xkbcomp.
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 confidenceBuffer overflow vulnerability in X.Org Server's XKB (X Keyboard Extension) component before version 1.19.4. An authenticated local attacker can inject large or malformed XKB-related atoms, overflowing a global buffer and causing X server crashes or potentially 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
Debian LinuxOperating system
= 8.0= 9.0<= 1.19.3CVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:L/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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Check installed X.Org Server versionRun `Xorg -version` or `X -version` and note the release number. On Debian-based systems, also run `dpkg -l | grep xserver-xorg-core` to see the installed package version.Affected if The version displayed is 1.19.3 or lower.
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Confirm XKB extension is activeCheck the X server log file (typically /var/log/Xorg.0.log) for lines containing 'XKB' or 'xkb' during server startup. You can also query the running X server with `xlsatoms -root | wc -l` to see if XKB atoms are being handled.Affected if XKB extension initializes and X atoms related to keyboard configuration are present (default state in most configurations).
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Verify X server access controlCheck the X server access control setting by running `xauth list` or examining /etc/X11/xorg.conf for 'DisableACcessControl' directives. Also verify which users have access with `xhost` without arguments.Affected if Access control allows untrusted or unauthenticated users to connect to the X server (xhost + or no access control restrictions).
You are affected if X.Org Server version is 1.19.3 or lower AND the XKB extension is enabled (which is the default), regardless of access control since the CVE specifies authenticated local attackers.
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 dataUpgrade X.Org Server to version 1.19.4 or later. Until patched, restrict X server access to trusted, authenticated users only.
Fix this in Debian Linux
Scoped from the published advisory
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-13723 — 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-2017-13723 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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