dbcve.org
Asr 5000 FirmwareOperating system · Cisco

CVE-2018-0117

HIGH · 8.6 CVSS v3.0 Published 2018-02-08
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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 · unedited
A vulnerability in the ingress packet processing functionality of the Cisco Virtualized Packet Core-Distributed Instance (VPC-DI) Software could allow an unauthenticated, remote attacker to cause both control function (CF) instances on an affected system to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient handling of user-supplied data by the affected software. An attacker could exploit this vulnerability by sending malicious traffic to the internal distributed instance (DI) network address on an affected system. A successful exploit could allow the attacker to cause an unhandled error condition on the affected system, which would cause the CF instances to reload and consequently cause the entire VPC to reload, resulting in the disconnection of all subscribers and a DoS condition on the affected system. This vulnerability affects Cisco Virtualized Packet Core-Distributed Instance (VPC-DI) Software N4.0 through N5.5 with the Cisco StarOS operating system 19.2 through 21.3. Cisco Bug IDs: CSCve17656.

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 confidence

A remote unauthenticated attacker can send specially crafted packets to the internal distributed instance (DI) network address on affected Cisco VPC-DI systems. Due to insufficient validation of user-supplied data in the ingress packet processing functionality, this triggers an unhandled error that causes both control function (CF) instances to reload, forcing the entire Virtual Packet Core to reload and disconnecting all subscribers.

MitigationApply the Cisco software update (CSCve17656) or upgrade to a StarOS version beyond 21.3 as indicated in the Cisco advisory.

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
Asr 5000 FirmwareOperating system
Affected:= 21.1.v0.66836= 21.1.v7= 21.3.0= 21.6.0
Asr 5500 FirmwareOperating system
Affected:= 21.1.v0.66836= 21.1.v7= 21.3.0= 21.6.0

CVSS 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
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the Cisco platform model
    Run 'show hardware' or 'show system' command to confirm the device is an ASR 5000 or ASR 5500 series
    Affected if Device model is not ASR 5000 or ASR 5500 - not affected
  2. Check the installed StarOS firmware version
    Run 'show version' or 'show build' command to display the firmware version
    Affected if Version matches 21.1.v0.66836, 21.1.v7, 21.3.0, or 21.6.0 - likely affected
  3. Verify VPC-DI distributed instance mode is enabled
    Run 'show distributed instance' or 'show vpc status' to confirm the system is configured in Distributed Instance (DI) mode
    Affected if System is not configured as a Distributed Instance - not vulnerable since flaw is in DI network packet processing
  4. Check DI network interface status and accessibility
    Run 'show ip interface' or 'show distributed instance network' to identify the internal DI network address and verify it is configured
    Affected if DI network interface is not configured or system is standalone (not DI) - not affected

User is affected if running ASR 5000/5500 with firmware version 21.1.v0.66836, 21.1.v7, 21.3.0, or 21.6.0 AND the system is configured in VPC-DI distributed instance mode with an active internal DI network interface.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the Cisco software update (CSCve17656) or upgrade to a StarOS version beyond 21.3 as indicated in the Cisco advisory.

Fix this in Asr 5000 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,480
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-0117 in production — separate from our analysis above.

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What this is

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.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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