CVE-2000-0408
MediumPublic exploitIIS 4.05 and 5.0 allow remote attackers to cause a denial of service via a long, complex URL that appears to contain a large number of file extensions, aka the "Malformed Extension Data in URL" vulnerability.
Published May 11, 2000 · Updated Apr 15, 2026
Key Facts
Patch immediately- CVE-2000-0408 is a medium-severity vulnerability (CVSS 5.0 v2) affecting Internet Information Server (Microsoft), Internet Information Services (Microsoft).
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 58% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v2
5.0
AV:N/AC:L/Au:N/C:N/I:N/A:P
EPSS (30-day exploit likelihood)
58%
Higher than 99.0% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2000-0408 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
IIS 4.05 and 5.0 allow remote attackers to cause a denial of service via a long, complex URL that appears to contain a large number of file extensions, aka the "Malformed Extension Data in URL" vulnerability.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Internet Information ServerMicrosoft | 4.0 | n/a |
| Internet Information ServicesMicrosoft | 5.0 | n/a |
Timeline
Publicly disclosed
May 11, 2000
Last updated
Apr 15, 2026
References
- exploitExploitDB-19907
- otherMS00-030
- otherQ260205
- other1190
- otherhttp://www.ussrback.com/labs40.html
FAQ
Common Questions.
IIS 4.05 and 5.0 allow remote attackers to cause a denial of service via a long, complex URL that appears to contain a large number of file extensions, aka the "Malformed Extension Data in URL" vulnerability.
Affected: Internet Information Server (Microsoft) versions 4.0; Internet Information Services (Microsoft) versions 5.0. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
Is CVE-2000-0408 Running On Your Attack Surface?
Brandefense maps vulnerabilities like this one to your internet-facing assets and tells you exactly where to patch.
Request A Demo