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Vpn 3000 Concentrator Series SoftwareOperating system · Cisco

CVE-2002-1102

MEDIUM · 5.0 CVSS v2.0 Published 2002-10-04
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
59/100
Remediation priority · Elevated
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
The LAN-to-LAN IPSEC capability for Cisco VPN 3000 Concentrator 2.2.x, and 3.x before 3.5.4, allows remote attackers to cause a denial of service via an incoming LAN-to-LAN connection with an existing security association with another device on the remote network, which causes the concentrator to remove the previous connection.

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 confidence

In Cisco VPN 3000 Concentrator versions 2.2.x and 3.x before 3.5.4, a vulnerability exists in the LAN-to-LAN IPSEC capability where an incoming connection with a conflicting security association (SA) to an existing remote device causes the concentrator to improperly remove the previous legitimate connection, resulting in denial of service for established VPN tunnels.

MitigationUpgrade Cisco VPN 3000 Concentrator to version 3.5.4 or later to remediate this vulnerability. Prior to upgrade, ensure configuration backups are secured and plan for appropriate maintenance windows.

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
Vpn 3000 Concentrator Series SoftwareOperating system
Affected:= 2.0= 2.5.2.a= 2.5.2.b= 2.5.2.c= 2.5.2.d= 2.5.2.f= 3.0= 3.0\(rel\)= 3.0.3.a= 3.0.3.b= 3.0.4= 3.1
Vpn 3002 Hardware ClientApplication
Affected:all versions

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
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial

AV:N/AC:L/Au:N/C:N/I:N/A:P

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. Identify the VPN device model
    Locate the hardware model number on the Cisco VPN 3000 Concentrator chassis or in the device inventory. Confirm it is either a VPN 3000 Concentrator Series or a VPN 3002 Hardware Client.
    Affected if The device is a VPN 3002 Hardware Client (all versions are affected) or a VPN 3000 Concentrator Series.
  2. Determine the software version
    Access the device management interface (web or CLI) and navigate to the System > General > Version or equivalent section to view the installed software version. Compare against the affected list: 2.0, 2.5.2.a, 2.5.2.b, 2.5.2.c, 2.5.2.d, 2.5.2.f, 3.0, 3.0(rel), 3.0.3.a, 3.0.3.b, 3.0.4, or 3.1.
    Affected if The installed version is any of the versions listed, or any version below 3.5.4 for the 2.2.x and 3.x lines.
  3. Verify LAN-to-LAN IPSEC is configured
    In the device management interface, review the VPN configuration sections (VPN > IPSEC > LAN-to-LAN or similar) to determine if any LAN-to-LAN IPSEC tunnels are defined and active.
    Affected if LAN-to-LAN IPSEC tunnels are configured and active on the device.
  4. Review recent VPN tunnel status
    Check the IPSEC Active Tunnel List or VPN connection logs for evidence of unexpected tunnel disconnections, particularly where legitimate tunnels are being dropped when new connections with conflicting Security Associations are attempted.
    Affected if Established VPN tunnels are being terminated or dropped unexpectedly when new LAN-to-LAN connections are initiated.

A user is affected if they are running a VPN 3000 Concentrator (versions 2.0 through 3.1) or any VPN 3002 Hardware Client version with LAN-to-LAN IPSEC tunnels configured, and they observe unexplained tunnel drops when new connections are attempted.

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 VPN 3000 Concentrator to version 3.5.4 or later to remediate this vulnerability. Prior to upgrade, ensure configuration backups are secured and plan for appropriate maintenance windows.

Fix this in Vpn 3000 Concentrator Series 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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Scan for this in your stack

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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-2002-1102 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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