Ios XrOperating system · Cisco
CVE-2016-9205
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 vulnerability in the HTTP 2.0 request handling code of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause the Event Management Service daemon (emsd) to crash, resulting in a denial of service (DoS) condition. More Information: CSCvb14425. Known Affected Releases: 6.1.1.BASE. Known Fixed Releases: 6.1.2.6i.MGBL 6.1.22.9i.MGBL 6.2.1.14i.MGBL.
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 vulnerability in the HTTP 2.0 request handling code of Cisco IOS XR Software allows an unauthenticated remote attacker to crash the Event Management Service daemon (emsd) by sending specially crafted HTTP 2.0 requests, resulting in denial of service.
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
Ios XrOperating system
= 6.1.1CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/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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Confirm Cisco IOS XR is runningIdentify the system type and verify it is Cisco IOS XR software. Use 'show version' or 'uname -a' to check the operating system.Affected if The system is not running Cisco IOS XR.
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Check the IOS XR versionRun 'show version' or 'admin show version' to display the installed IOS XR version.Affected if The installed version is exactly 6.1.1, as this is the only affected version listed.
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Verify HTTP 2.0 is enabled for Event Management ServiceCheck the emsd configuration to determine if HTTP 2.0 protocol support is enabled. Look for HTTP 2.0 related settings in the emsd or web engine configuration.Affected if HTTP 2.0 is explicitly enabled for the Event Management Service.
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Confirm emsd is network accessibleCheck if the Event Management Service daemon (emsd) is listening on network interfaces and accessible remotely. Review the service binding and access control settings.Affected if emsd is exposed to network access and HTTP 2.0 handling is active.
You are affected only if the system runs Cisco IOS XR version 6.1.1 with HTTP 2.0 enabled for the Event Management Service and emsd is network-accessible.
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 fixed software releases (6.1.2.6i.MGBL, 6.1.22.9i.MGBL, or 6.2.1.14i.MGBL) or later versions. As a temporary workaround, consider implementing network-level filtering to block suspicious HTTP 2.0 traffic until the patch can be applied.
Fix this in Ios Xr
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 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 $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-9205 — 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-2016-9205 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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