Sygate Personal FirewallApplication · Symantec

CVE-2002-2397

HIGH · 10.0 CVSS v2.0 Published 2002-12-31
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
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
Sygate personal firewall 5.0 could allow remote attackers to bypass firewall filters via spoofed (1) source IP address of 127.0.0.1 or (2) network address of 127.0.0.0.

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

Sygate Personal Firewall 5.0 contains a flaw where it fails to properly validate the source IP address of incoming network packets. The firewall can be bypassed by attackers who spoof the source IP to appear as 127.0.0.1 (localhost) or any address in the 127.0.0.0/8 loopback range. Since the firewall trusts loopback addresses without verifying they originated from the local machine, remote attackers can bypass all firewall filtering rules and gain unauthorized access.

MitigationUpgrade from Sygate Personal Firewall 5.0 to a current, supported firewall solution that properly validates that loopback addresses can only originate from the local interface, or implement network-level filtering to drop any inbound packets with source addresses in the 127.0.0.0/8 range at the perimeter.

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
Sygate Personal FirewallApplication
Affected:= 5.0

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
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

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

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. Verify if Sygate Personal Firewall 5.0 is installed
    Check the system for Sygate Personal Firewall installation. On Windows, examine the program files directory for Sygate folder, or check the Windows Registry under HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall for an entry named 'Sygate Personal Firewall' or similar.
    Affected if The software is present and the version listed is 5.0 builds 1218 or below (the specific 5.0 release).
  2. Confirm the exact version number
    Locate the version information of the installed Sygate Personal Firewall. Right-click on the executable (typically sfw.exe in the Sygate installation folder) and select Properties, then view the Details tab for version info, or run the program and check About/Help menu.
    Affected if The displayed version is exactly 5.0.x (where x represents any 5.0 build).
  3. Verify the firewall service is running
    Open Windows Services (services.msc) and look for 'Sygate Personal Firewall' service, or check the system tray for the Sygate icon indicating the firewall is active.
    Affected if The Sygate Personal Firewall service is running and actively filtering network traffic.

You are affected if Sygate Personal Firewall version 5.0 is installed and running on your system, as the firewall will trust any incoming packet with a 127.0.0.0/8 source address without validating it originated locally.

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 from Sygate Personal Firewall 5.0 to a current, supported firewall solution that properly validates that loopback addresses can only originate from the local interface, or implement network-level filtering to drop any inbound packets with source addresses in the 127.0.0.0/8 range at the perimeter.

Fix this in Sygate Personal Firewall Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2002-2397 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
  • No weaponised exploit code, or anything meant to cause harm
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