dbcve.org
iOSOperating system · Cisco

CVE-2015-6359

MEDIUM · 6.1 CVSS v2.0 Published 2015-12-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
66/100
Remediation priority · Elevated
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
The Neighbor Discovery (ND) protocol implementation in the IPv6 stack in Cisco IOS 15.3(3)S0.1 on ASR devices mishandles internal tables, which allows remote attackers to cause a denial of service (memory consumption or device crash) via a flood of crafted ND messages, aka Bug ID CSCup28217.

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

The Neighbor Discovery (ND) protocol implementation in the IPv6 stack in Cisco IOS 15.3(3)S0.1 on ASR devices mishandles internal tables when processing crafted ND messages. A remote attacker can trigger memory consumption or device crash by flooding the device with specially crafted ND messages.

MitigationApply the applicable Cisco IOS security update to affected ASR devices. Additionally, implement IPv6 traffic filtering at network edges to block malicious or unexpected ND messages until the update can be deployed.

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
iOSOperating system
Affected:= 15.2\(4\)e= 15.2\(4\)pi= 15.2\(4\)st= 15.2\(5\)st= 15.3\(3\)s0.1

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
Adjacent
Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete

AV:A/AC:L/Au:N/C:N/I:N/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 checks

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

  1. Identify device model
    Run 'show version' or 'show platform' command and confirm the device is a Cisco ASR series router
    Affected if Device is NOT an ASR model (vulnerability only affects ASR devices)
  2. Check Cisco IOS version
    Run 'show version' and locate the IOS version string in the output
    Affected if Version matches 15.2(4)e, 15.2(4)pi, 15.2(4)st, 15.2(5)st, or 15.3(3)s0.1 exactly
  3. Verify IPv6 is enabled
    Run 'show ipv6 interface brief' to list IPv6-enabled interfaces; if no interfaces appear with IPv6 addresses, IPv6 may be disabled
    Affected if IPv6 is enabled on any interface (vulnerability requires active IPv6 stack)
  4. Assess network exposure
    Review access control lists and interface configurations to determine if the device management or transit interfaces are reachable from untrusted networks
    Affected if Device is directly accessible from external networks without IPv6 traffic filtering

Device is affected if it is a Cisco ASR running one of the listed IOS versions with IPv6 enabled and accessible to untrusted networks.

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 applicable Cisco IOS security update to affected ASR devices. Additionally, implement IPv6 traffic filtering at network edges to block malicious or unexpected ND messages until the update can be deployed.

Fix this in iOS Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
Get help mitigating

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 locally
dbcve dependency scanner

Check whether your project pulls in CVE-2015-6359 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2015-6359 in production — separate from our analysis above.

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.

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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data