CVE-1999-1254
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 · uneditedWindows 95, 98, and NT 4.0 allow remote attackers to cause a denial of service by spoofing ICMP redirect messages from a router, which causes Windows to change its routing tables.
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 confidenceRemote attackers can spoof ICMP redirect messages impersonating a router, causing vulnerable Windows 95, 98, and NT 4.0 systems to incorrectly modify their routing tables, resulting in a denial of service due to disrupted network connectivity.
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 dataall versionsall versionsall 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 Windows operating system versionRun 'winver' from the command prompt or check System Properties to determine if the OS is Windows 95, Windows 98, or Windows NT 4.0Affected if The system is running any version of Windows 95, Windows 98, or Windows NT 4.0 - all versions of these operating systems are affected
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Verify ICMP redirect handling is enabledCheck the registry key 'HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters\EnableICMPRedirect' - a value of 1 means ICMP redirects are acceptedAffected if ICMP redirects are enabled (value is 1 or the key does not exist, defaulting to enabled in these Windows versions)
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Confirm network connectivity statusUse 'ping' or 'tracert' to test basic network connectivity and observe if routes are being redirected unexpectedly or if connectivity is disruptedAffected if Network connectivity is intermittent, inconsistent, or routes appear to be redirected to unexpected gateways
The environment is affected if it runs Windows 95, Windows 98, or Windows NT 4.0 (any version) with ICMP redirects enabled, as these legacy operating systems accept spoofed ICMP redirect messages by default.
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 dataFilter or disable ICMP redirects at the network perimeter router/firewall, or upgrade from these legacy Windows versions as they are no longer supported.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-1999-1254 — 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-1999-1254 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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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