CVE-2020-25697
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 privilege escalation flaw was found in the Xorg-x11-server due to a lack of authentication for X11 clients. This flaw allows an attacker to take control of an X application by impersonating the server it is expecting to connect to.
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 privilege escalation vulnerability exists in Xorg-x11-server where the server fails to properly authenticate incoming X11 client connections. An attacker can impersonate the legitimate X server and intercept connections from X applications, allowing them to capture keystrokes, screen content, and potentially inject malicious input to applications.
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 dataall 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
- Local
- Complexity
- High
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/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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Verify Xorg-x11-server package is installedCheck for the installed package using your package manager (e.g., rpm -qa | grep xorg-x11-server, dpkg -l | grep xserver-xorg, or yum list installed xorg-x11-server)Affected if The package is installed and running - all versions of X.org X Server are affected by this vulnerability
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Identify if X server is listening on network interfacesRun 'ss -tlnp | grep -E "(:600[0-9]|:601[0-9]|:62[0-9][0-9])"' or 'netstat -tlnp | grep X' to see if X display ports (6000-6099) are open on non-loopback interfacesAffected if X server is bound to 0.0.0.0 or a public IP address rather than only 127.0.0.1 (localhost)
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Check X server authentication configurationInspect /etc/X11/xorg.conf or run 'xauth list' to see what authentication tokens exist, and check for .Xauthority or .Xauthority-lOCALHOST filesAffected if X server is using weak or no authentication (MIT-MAGIC-COOKIE-1 with no restrictions) or has no xauth tokens configured for remote connections
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Determine if X11 connections are tunneled securelyReview how X applications connect - check if users rely on raw X11 connections (DISPLAY variable pointing to hostname:0) rather than SSH X11 forwarding (SSH -X or SSH -Y)Affected if Users connect directly to the X server over the network without SSH tunneling or other encryption/authentication wrappers
An organization is affected if Xorg-x11-server is running and accepting network connections without proper authentication mechanisms like SSH X11 forwarding or strong xauth controls.
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 the vendor patch to Xorg-x11-server and ensure X11 connections use proper authentication mechanisms such as X11 forwarding over SSH or xauth.
- Consultation2.0 h
- Implementation2.0 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 $2,752.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-25697 — 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-2020-25697 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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