Adaptive Security Appliance SoftwareOperating system · Cisco
CVE-2017-3867
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 · uneditedA vulnerability in the Border Gateway Protocol (BGP) Bidirectional Forwarding Detection (BFD) implementation of Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to bypass the access control list (ACL) for specific TCP and UDP traffic. More Information: CSCvc68229. Known Affected Releases: 9.6(2). Known Fixed Releases: 99.1(20.1) 99.1(10.2) 98.1(12.7) 98.1(1.49) 97.1(6.58) 97.1(0.134) 96.2(0.109) 9.7(1.1) 9.6(2.99) 9.6(2.8).
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 · moderate confidenceA vulnerability in the BGP Bidirectional Forwarding Detection (BFD) implementation within Cisco Adaptive Security Appliance (ASA) Software allows an unauthenticated remote attacker to bypass access control lists for specific TCP and UDP traffic. The flaw is a logic bypass in the firewall's ACL enforcement rather than a direct code execution flaw.
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
Adaptive Security Appliance SoftwareOperating system
= 6.3.1= 9.6.2= 9.6.2.1= 9.6.2.2= 9.6.2.3= 9.6.2.7= 9.6.2.8= 9.6.2.9= 9.6.3CVSS 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
- Low
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
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.
-
Identify Cisco ASA device and versionLog into the ASA CLI and run the command 'show version' to display the running software version. Alternatively, use ASDM to check the device dashboard for the software version.Affected if The displayed version matches one of the affected versions: 6.3.1, 9.6.2, 9.6.2.1, 9.6.2.2, 9.6.2.3, 9.6.2.7, 9.6.2.8, 9.6.2.9, or 9.6.3.
-
Verify BFD feature is enabledRun the command 'show bfd summary' or 'show bfd neighbors' in the ASA CLI. If BFD is not configured, these commands will show no neighbors or indicate BFD is not active.Affected if BFD is actively configured and running on the ASA (output shows BFD neighbors or BFD is enabled in the configuration).
-
Confirm BGP is configured with BFDRun 'show running-config | include bfd' to search for BFD configuration lines, and 'show running-config | include router bgp' to check for BGP routing configuration. BFD is commonly deployed with BGP neighbors.Affected if BGP routing is configured on the ASA with BFD enabled for neighbor sessions.
You are affected if your Cisco ASA runs an affected version listed above AND has BFD enabled (especially with BGP), as the logic bypass only triggers when BFD processes the specific traffic.
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 dataUpgrade Cisco ASA Software to one of the fixed releases (9.6(2.99), 9.7(1.1), or later) to remediate this vulnerability. Alternatively, implement additional network segmentation or filtering to restrict BGP/BFD traffic at perimeter devices.
Fix this in Adaptive Security Appliance Software
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 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 $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-3867 — 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-2017-3867 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
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.
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.
- 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