Vpn 3000 Concentrator Series SoftwareOperating system · Cisco
CVE-2002-1095
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 · uneditedCisco VPN 3000 Concentrator before 2.5.2(F), with encryption enabled, allows remote attackers to cause a denial of service (reload) via a Windows-based PPTP client with the "No Encryption" option set.
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 confidenceThe Cisco VPN 3000 Concentrator before version 2.5.2(F) contains a denial of service vulnerability when encryption is enabled and a remote user connects using a Windows PPTP client configured with the 'No Encryption' option. The device mishandles the encryption negotiation mismatch, causing it to reload unexpectedly.
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
= 2.0= 2.5.2.a= 2.5.2.b= 2.5.2.c= 2.5.2.d
Secure Access Control ServerApplication
= 2.6.3
Vpn 3002 Hardware ClientApplication
all versionsCVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify the VPN Concentrator model and firmware versionAccess the device administration interface or use CLI to display the firmware version (for example, via 'show version' or through the web-based admin console)Affected if The firmware version is 2.0, 2.5.2.a, 2.5.2.b, 2.5.2.c, or 2.5.2.d (versions prior to 2.5.2(F))
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Verify whether PPTP is enabled on the VPN ConcentratorCheck the device configuration for PPTP settings (typically found in the PPTP configuration menu or via 'show run' in CLI)Affected if PPTP feature is enabled and configured on the device
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Confirm encryption is enabled for VPN connectionsReview the VPN encryption policy or tunnel settings in the device configurationAffected if Encryption is enabled for PPTP or general VPN connections
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Check Cisco Secure Access Control Server version if deployedIf ACS is in use, verify its version through the admin interface or system informationAffected if The ACS version is exactly 2.6.3 and PPTP authentication is in use
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Check VPN 3002 Hardware Client statusIdentify if any VPN 3002 Hardware Client devices are deployed and whether PPTP is configuredAffected if A VPN 3002 Hardware Client is in use with PPTP enabled (all versions of this model are affected)
A user is affected if they run a Cisco VPN 3000 Concentrator (or 3002 Hardware Client) on vulnerable firmware versions (prior to 2.5.2(F)) with PPTP enabled and encryption configured, particularly when Windows PPTP clients may connect with No Encryption option.
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 the Cisco VPN 3000 Concentrator firmware to version 2.5.2(F) or later. If PPTP is not required, consider disabling the PPTP feature to reduce attack surface.
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
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2002-1095 — 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-2002-1095 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
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- Version or environment caveats, and links to real fixes
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