Ios XeOperating system · Cisco
CVE-2016-1348
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 · uneditedCisco IOS 15.0 through 15.5 and IOS XE 3.3 through 3.16 allow remote attackers to cause a denial of service (device reload) via a crafted DHCPv6 Relay message, aka Bug ID CSCus55821.
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 remote attacker can send a specially crafted DHCPv6 Relay message to vulnerable Cisco IOS (15.0-15.5) or IOS XE (3.3-3.16) devices, causing the device to reload unexpectedly, 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 XeOperating system
= 3.3xo_3.3.0xo= 3.3xo_3.3.1xo= 3.3xo_3.3.2xo= 3.5e_3.5.0e= 3.5e_3.5.1e= 3.5e_3.5.2e= 3.5e_3.5.3e= 3.5s_3.5.0s= 3.5s_3.5.1s= 3.5s_3.5.2s= 3.6e_3.6.0e= 3.6e_3.6.1e< 2017-01-06= t-ms14jakucb-1102.5= snv_124< 2.50\(aazi.0\)c0= 3.08CVSS 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 DHCPv6 Relay feature is enabledExecute 'show ipv6 dhcp relay' or 'show running-config | include dhcp' to see if DHCPv6 relay is configured on any interfaceAffected if DHCPv6 relay is enabled and the device is running a vulnerable IOS/IOS XE version
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Identify the IOS or IOS XE versionExecute 'show version' or 'show version | include Version' to retrieve the installed software versionAffected if The version falls within IOS 15.0-15.5 or IOS XE 3.3-3.16 (compare your version to these ranges)
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Check for IPv6 interface configurationExecute 'show ipv6 interface brief' to list all interfaces with IPv6 enabledAffected if Interfaces have IPv6 addresses and DHCPv6 relay is pointing to those interfaces
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Verify DHCPv6 relay destination configurationExecute 'show running-config | include ipv6 dhcp relay' to see if a relay destination address is configuredAffected if A relay destination (helper address) is configured and the device is running a vulnerable version
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Confirm device is exposed to DHCPv6 trafficReview interface configurations for 'ipv6 dhcp relay destination' statements or check if the device is acting as a DHCPv6 relay agent between external networksAffected if The device relay function is exposed to untrusted DHCPv6 messages from network segments outside your control
The device is affected if it runs Cisco IOS 15.0-15.5 or IOS XE 3.3-3.16 AND has DHCPv6 relay enabled and accessible to remote attackers.
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 data2.502017-01-06
Upgrade to a patched version of Cisco IOS or IOS XE that addresses this vulnerability. If immediate patching is not possible, consider filtering or rate-limiting DHCPv6 traffic at network boundaries to reduce attack surface.
Fix this in Ios Xe
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 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 $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-1348 — 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-2016-1348 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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