Pix Firewall SoftwareOperating system · Cisco

CVE-2016-6366

HIGH · 8.8 CVSS v3.1 Published 2016-08-18

Fix available

A fix is available. Upgrade to 9.0.4.40 / 9.1.7 or later.

See remediation →

100/100

Remediation priority · Urgent

In the wild High EPSS Public exploit Remotely reachable Zero-click

Official description

NVD · unedited

Buffer overflow in Cisco Adaptive Security Appliance (ASA) Software through 9.4.2.3 on ASA 5500, ASA 5500-X, ASA Services Module, ASA 1000V, ASAv, Firepower 9300 ASA Security Module, PIX, and FWSM devices allows remote authenticated users to execute arbitrary code via crafted IPv4 SNMP packets, aka Bug ID CSCva92151 or EXTRABACON.

Technical summary

dbcve analysis · high confidence

Buffer overflow vulnerability in Cisco Adaptive Security Appliance (ASA) Software's SNMP implementation allows remote authenticated users to execute arbitrary code via crafted IPv4 SNMP packets. The vulnerability affects multiple ASA platforms including ASA 5500, ASA 5500-X, ASA Services Module, ASA 1000V, ASAv, Firepower 9300 ASA Security Module, PIX, and FWSM devices running software versions through 9.4.2.3.

MitigationUpdate Cisco ASA Software to a version that addresses CSCva92151. If immediate patching is not feasible, restrict SNMP access to trusted management networks only and consider disabling SNMP if not required.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions

NVD · CPE data

Pix Firewall SoftwareOperating system

Affected:all versions

Adaptive Security Appliance SoftwareOperating system

Affected:>= 7.2.1, < 9.0.4.40>= 9.1.1, < 9.1.7$9$>= 9.2.0, < 9.2.4$14$>= 9.3.0, < 9.3.3$10$>= 9.4.0.115, < 9.4.3$8$>= 9.5.0, <= 9.5$3$>= 9.6.0, < 9.6.1$11$

Asa 1000v Cloud Firewall SoftwareOperating system

Affected:= 8.7.1= 8.7.1.1

CVSS breakdown

From the vector

Attack vector: Network
Complexity: Low
Privileges: Low
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

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

Am I affected?

dbcve checks

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

Identify the device and software version

Log into the ASA CLI and run 'show version' to display the running Cisco ASA Software version and model information

Affected if The device runs Cisco ASA Software or Cisco Pix Firewall Software and the version falls within the affected ranges: 7.2.1 to 9.0.4.40, 9.1.1 to 9.1.7(9), 9.2.0 to 9.2.4(14), 9.3.0 to 9.3.3(10), 9.4.0.115 to 9.4.3(8), 9.5.0 to 9.5(3), or 9.6.0 to 9.6.1(11); or any version of Cisco Pix Firewall Softwa
Verify if SNMP is enabled

Run 'show snmp-server' or 'show run snmp-server' in the ASA CLI to check whether SNMP is configured and active

Affected if SNMP is enabled on the device (the vulnerability is exploited via specially crafted IPv4 SNMP packets)
Check SNMP access control configuration

Run 'show snmp-server group' and 'show snmp-server community' to view SNMP community strings and access list bindings

Affected if SNMP community strings are configured and accessible to untrusted networks, particularly if 'snmp-server community' or 'snmp-server group' shows no ACL restriction or uses an overly permissive access list
Review SNMP version and configuration

Run 'show run all snmp-server' to see full SNMP configuration including version (v2c or v3) and any trap/inform settings

Affected if SNMP v2c is in use with default or weak community strings, or SNMP access is not restricted to specific management IP addresses

The environment is affected if the Cisco ASA or Pix Software version is within the vulnerable ranges AND SNMP is enabled with access accessible to the attacker (untrusted networks or weak SNMP credentials).

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

Remediation

dbcve · scoped

Upgrade available Upgrade to 9.0.4.40 / 9.1.7 / 9.2.4 or later

Fixed in 9.0.4.409.1.79.2.4

Interim mitigation

Update Cisco ASA Software to a version that addresses CSCva92151. If immediate patching is not feasible, restrict SNMP access to trusted management networks only and consider disabling SNMP if not required.

Recommended fix High confidence

Upgrade to the minimum fixed version for your branch: 9.0.4.40, 9.1.7(9), 9.2.4(14), or 9.3.3(10); or migrate PIX devices to supported ASA software

Identify the current Cisco ASA or PIX software version using 'show version' command
Determine which version branch you are running (7.2.x, 9.0.x, 9.1.x, 9.2.x, or 9.3.x) from the identified version
For ASA 9.0.x branch: upgrade to version 9.0.4.40 or later
For ASA 9.1.x branch: upgrade to version 9.1.7(9) or later
For ASA 9.2.x branch: upgrade to version 9.2.4(14) or later
For ASA 9.3.x branch: upgrade to version 9.3.3(10) or later
For PIX devices: migrate to a supported ASA version as PIX is end-of-life
For Asa 1000v: upgrade from 8.7.1/8.7.1.1 to a supported version (9.1.7(9) or later recommended)

Caveat PIX devices are end-of-life and require migration to ASA; review Cisco migration guides and test thoroughly before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Pix Firewall Software Exploited in the wild — priority engagement

Consultation8.0 h
Implementation4.0 h
Testing8.0 h
Review / QA4.0 h

24.0 hours of engineering $4,240

Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,784.

Scan for this in your stack

Free · runs locally

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References

Primary sources

blogs.cisco.comProof of Concept
blogs.cisco.comExploitPress/Media CoverageVendor Advisory
tools.cisco.comVendor Advisory
tools.cisco.comVendor Advisory
www.securityfocus.comBroken LinkNot ApplicableThird Party AdvisoryVDB Entry
www.securitytracker.comBroken LinkThird Party AdvisoryVDB Entry
www.exploit-db.comThird Party AdvisoryVDB Entry
zerosum0x0.blogspot.comExploitTechnical Description
github.comBroken LinkExploit
www.cisa.govUS Government Resource
nvd.nist.govNVD record

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2016-6366 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2016-6366?

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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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

At a glance

Exploited in the wildOn CISA’s known-exploited list · agencies must fix by 2022-06-14

A fix existsUpgrade to 9.0.4.40 / 9.1.7 or later

Severity 8.8 High

Exploit likelihood EPSS, next 30 days 87.6%

Affects: Pix Firewall Software

Remediation

Being exploited — close it fast

Fix this in Pix Firewall Software 24 hrs · Moderate

Typical engagement from $4,240

Get it fixed fast See the full breakdown ↓

This CVE is on CISA’s actively-exploited list, so the clock is real — a vetted specialist can deliver a reviewed fix for your staging environment quickly.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

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.

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.

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.

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.

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.

Check your environment

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.

Scan for this in your stack

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Am I affected?

Remediation

References