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Virtualized Packet CoreApplication · Cisco

CVE-2017-6678

HIGH · 7.5 CVSS v3.0 Published 2017-06-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
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 UDP packet processing functionality of Cisco Virtualized Packet Core-Distributed Instance (VPC-DI) Software 19.2 through 21.0 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 crafted UDP packets to the distributed instance (DI) network addresses of both CF instances 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 can be exploited via IPv4 traffic only. Cisco Bug IDs: CSCvc01665 CSCvc35565.

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

This vulnerability in Cisco VPC-DI Software versions 19.2-21.0 allows unauthenticated remote attackers to cause denial of service by sending crafted UDP packets to the distributed instance network addresses of both control function (CF) instances. The insufficient handling of user-supplied data in the ingress UDP packet processing triggers an unhandled error condition, causing both CF instances to reload and the entire VPC to fail.

MitigationApply the Cisco patch (software version 21.1 or later per the 'through 21.0' affected range) to remediate the insufficient input validation in the UDP packet handler. Consider network segmentation to limit exposure of the DI network interfaces if immediate patching is not feasible.

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
Virtualized Packet CoreApplication
Affected:= v19.2_base= v19.3_base= v20.0_base= v20.1_base= v20.2_base= v21.0_base

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
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 checks

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

  1. Identify the installed VPC-DI software version
    Access the VPC-DI CLI and run 'show version' or 'show software' to display the installed software version
    Affected if The version displayed is any of: 19.2_base, 19.3_base, 20.0_base, 20.1_base, 20.2_base, or 21.0_base
  2. Confirm the product is Cisco Virtualized Packet Core
    Run 'show system' or 'show chassis' to verify the platform is VPC-DI (Virtualized Packet Core - Distributed Instance)
    Affected if The product is confirmed as Cisco VPC-DI and version falls within the affected range
  3. Check for CF reload events or crash logs
    Run 'show logging' or 'show crash' commands to look for recent reload events or error messages related to CF (Control Function) instances
    Affected if Recent reloads of both CF instances are observed without an apparent administrative cause
  4. Verify DI network interface exposure
    Run 'show ip interface brief' to identify the distributed instance (DI) network interface IP addresses and check if UDP traffic on these interfaces is reachable from untrusted networks
    Affected if DI network interfaces are accessible from networks where unauthenticated attackers could send UDP packets
  5. Review recent UDP packet processing errors
    Run 'show logging' or 'show buffer' commands to search for UDP packet handling errors, unhandled exceptions, or packet processing failures in the logs
    Affected if Error messages indicate failures in UDP packet processing that correlate with CF reload events

If running any Cisco VPC-DI version from 19.2_base through 21.0_base with exposed DI network interfaces, the environment is likely affected by this vulnerability.

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 patch (software version 21.1 or later per the 'through 21.0' affected range) to remediate the insufficient input validation in the UDP packet handler. Consider network segmentation to limit exposure of the DI network interfaces if immediate patching is not feasible.

Fix this in Virtualized Packet Core 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-2017-6678 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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