dbcve.org
Netflow Generation Appliance SoftwareOperating system · Cisco

CVE-2017-3826

HIGH · 7.5 CVSS v3.0 Published 2017-03-01
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable 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
A vulnerability in the Stream Control Transmission Protocol (SCTP) decoder of the Cisco NetFlow Generation Appliance (NGA) with software before 1.1(1a) could allow an unauthenticated, remote attacker to cause the device to hang or unexpectedly reload, causing a denial of service (DoS) condition. The vulnerability is due to incomplete validation of SCTP packets being monitored on the NGA data ports. An attacker could exploit this vulnerability by sending malformed SCTP packets on a network that is monitored by an NGA data port. SCTP packets addressed to the IP address of the NGA itself will not trigger this vulnerability. An exploit could allow the attacker to cause the appliance to become unresponsive or reload, causing a DoS condition. User interaction could be needed to recover the device using the reboot command from the CLI. The following Cisco NetFlow Generation Appliances are vulnerable: NGA 3140, NGA 3240, NGA 3340. Cisco Bug IDs: CSCvc83320.

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

A vulnerability in the SCTP decoder of Cisco NetFlow Generation Appliance (NGA) versions before 1.1(1a) allows an unauthenticated remote attacker to cause a DoS by sending malformed SCTP packets on a network monitored by NGA data ports. The vulnerability stems from incomplete validation of SCTP packets, causing the device to hang or unexpectedly reload.

MitigationUpgrade Cisco NGA software to version 1.1(1a) or later to patch the SCTP decoder validation 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
Netflow Generation Appliance SoftwareOperating system
Affected:= 1.0\(2\)= 1.0.0= 1.1\(1\)= 1.1.0

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
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 checks

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

  1. Determine installed NGA software version
    Access the NGA CLI or web interface and retrieve the current software version (typically via 'show version' command in CLI or System > Software in web UI)
    Affected if Version displayed is 1.0(2), 1.0.0, 1.1(1), or 1.1.0 (any version before 1.1(1a))
  2. Confirm SCTP decoder is active
    Check NGA configuration for enabled protocols on data monitoring ports - look for SCTP as an enabled protocol in the NetFlow collection settings or decoder configuration
    Affected if SCTP protocol decoding is enabled and the device is processing SCTP traffic on monitored interfaces
  3. Identify monitored networks for SCTP exposure
    Review the NGA data port bindings to determine which network segments are being monitored - check which interfaces are configured as data collection ports
    Affected if NGA data ports are monitoring network segments that carry SCTP traffic (typically port 3643 or SCTP-based applications)
  4. Look for device instability symptoms
    Check system logs, crash logs, or console output for unexpected reloads, hangs, or error messages related to SCTP packet processing
    Affected if Device has experienced unexplained reloads or hangs, particularly after SCTP traffic was observed on monitored ports

You are affected if your NGA runs any version before 1.1(1a), has SCTP decoding enabled, and monitors networks carrying SCTP traffic - in that configuration, malformed SCTP packets can cause device hangs or reloads.

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

Upgrade Cisco NGA software to version 1.1(1a) or later to patch the SCTP decoder validation flaw.

Fix this in Netflow Generation Appliance Software Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
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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-2017-3826 in production — separate from our analysis above.

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
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  • No spam, self-promotion, credentials, or personal data