CVE-2011-1763
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 · uneditedThe get_free_port function in Xen allows local authenticated DomU users to cause a denial of service or possibly gain privileges via unspecified vectors involving a new event channel port.
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 confidenceThe get_free_port function in Xen contains a vulnerability in event channel port allocation handling. Local authenticated users running in guest domains (DomU) can exploit unspecified vectors in the get_free_port function to cause a denial of service on the hypervisor or potentially escalate privileges through improper event channel port management.
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
- Adjacent
- Complexity
- Low
- Authentication
- Single
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:A/AC:L/Au:S/C:C/I:C/A:C
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.
-
Verify Xen hypervisor is in useCheck system for Xen hypervisor presence. On Linux hosts, inspect /proc/xen for xen capabilities, run 'xm info' or 'xl info' to query hypervisor details, or check for xen kernel modules. On the hypervisor host itself, confirm Xen is the virtualization platform.Affected if The system is running Xen as the hypervisor and hosts guest domains (DomU)
-
Identify Xen versionRun 'xm info' or 'xl info' on the hypervisor host to retrieve the Xen version string. Compare the installed version against the vendor's release notes for this CVE.Affected if Any version of Xen is installed, since all versions are affected according to the CVE data
-
Confirm DomU guest configurationList running guest domains using 'xm list' or 'xl list' to identify any active DomU instances. Verify whether these guests have local authenticated access.Affected if Untrusted or less-trusted DomU guests with local user access are running on the Xen host
-
Check event channel access for guestsExamine the hypervisor configuration and guest domain settings to determine if event channel port allocation is accessible to DomU guests. In Xen, event channels are used for inter-domain communication. Verify guest privileges regarding port allocation mechanisms.Affected if DomU guests have the ability to trigger event channel port allocation operations
A user is affected if their environment runs a Xen hypervisor hosting DomU guests where local authenticated users can access event channel port allocation in the get_free_port function.
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 vendor-supplied patches or upgrade Xen to a version that addresses this vulnerability. Prioritize patching in environments where untrusted DomU guests have local access.
- Consultation4.0 h
- Implementation6.0 h
- Testing8.0 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 $6,080.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2011-1763 — 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-2011-1763 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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
- No spam, self-promotion, credentials, or personal data