CVE-2016-6415

The server IKEv1 implementation in Cisco IOS 12.2 through 12.4 and 15.0 through 15.6, IOS XE through 3.18S, IOS XR 4.3.x and 5.0.x through 5.2.x, and PIX before 7.0 allows remote attackers to obtain sensitive information from device memory via a Security Association (SA) negotiation request, aka Bug IDs CSCvb29204 and CSCvb36055 or BENIGNCERTAIN.

CVSS: 7.5Highscored by CISA
Exploited in the wild: Yes, in CISA KEV since 19 May 2023CISA deadline for US federal agencies: 9 Jun 2023public exploit code
EPSS: 87.7%chance of exploitation in the next 30 daystop 0.3% of scored CVEsFIRST score of 11 Nov 2026
Fix: Patch availablesee the advisories in the references
Published: 19 Sept 2016analysed here 12 Nov 2026

Do first. Apply updates per vendor instructions. (CISA's required action for this KEV entry)

Summary

Triage

Attack surface: Server-side
Exploitable: At runtime
Attack vector: network
Weakness: CWE-200 Information Exposure
Can a WAF block it?: Partly. See why

The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.

Affected products

Products named in our analysis

cisco:ios
cisco:ios_xe
cisco:ios_xr

Fix and mitigation

WAF and other mitigations

Can a WAF block it? Partly. Information exposure: some WAFs can scan responses and hide known leak patterns, such as stack traces or keys.

Also consider: response filtering

Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.

Remediation steps (AI-written)

Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.

Exploitation evidence

CISA KEV catalog: Listed since 19 May 2023.
CISA due date: 9 Jun 2023, the remediation deadline for US federal agencies
CISA required action: Apply updates per vendor instructions.
Public exploit code: Yes: 1 on Exploit-DB · 1 Metasploit module · 1 GitHub proof of concept
CISA SSVC: exploitation active, automatable yes, technical impact partialAssessed by CISA 8 Nov 2024 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.

Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.

Timeline

19 Sept 2016Published
17 Mar 2017First public exploit or proof of concept179 days (about 6 months) later
19 May 2023Added to CISA KEV (exploited in the wild)2,254 days (about 6 years) later
9 Jun 2023CISA remediation due date (US federal agencies)21 days later
8 Nov 2024CISA SSVC assessment: exploitation active519 days (about 1 year) later
12 Jan 2026CVE record last updated430 days (about 1 year) later
12 Nov 2026Analysed by vulneraibility.com304 days (about 10 months) later

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Metric	Value	What it means
Attack vector	NetworkReachable over the internet or any routable network.	Reachable over the internet or any routable network.
Attack complexity	LowRepeatable attack, no special conditions.	Repeatable attack, no special conditions.
Privileges required	NoneThe attacker needs no prior access.	The attacker needs no prior access.
User interaction	NoneNo victim action needed.	No victim action needed.
Scope	UnchangedImpact stays within the vulnerable component.	Impact stays within the vulnerable component.
Confidentiality	HighTotal data disclosure possible.	Total data disclosure possible.
Integrity	NoneNo unauthorised modification.	No unauthorised modification.
Availability	NoneThe service stays up.	The service stays up.

Common questions

Is CVE-2016-6415 being exploited?

Yes. CVE-2016-6415 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.

How severe is CVE-2016-6415?

CVE-2016-6415 is rated High with a CVSS score of 7.5. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2016-6415?

Yes. A fix has been recorded for CVE-2016-6415. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What does CVE-2016-6415 affect?

CVE-2016-6415 affects cisco:ios, cisco:ios_xe, cisco:ios_xr. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

References

NVD CVE.org CVE Details Source

4 references in the CVE record, grouped by the tags the record gives them.

Advisories (1)

tools.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-20160916-ikev1

Where the data on this page comes from

CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
NVD: CVSS and CPE data
CISA KEV catalog: exploitation, date added, due date
CISA Vulnrichment (ADP): SSVC decision points
FIRST EPSS: exploit probability and percentile
Exploit-DB: published exploits
Metasploit Framework: exploit and scanner modules
PoC-in-GitHub: GitHub repositories that claim a proof of concept

Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.

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