Which products and versions are affected by CVE-1999-0874?

Affected: Internet Information Server (Microsoft) versions 4.0; Windows 2000 (Microsoft); Windows Nt (Microsoft) versions 4.0. The full list is in the CVE brief.

Is CVE-1999-0874 being exploited in the wild?

It is not listed in any known-exploited vulnerabilities catalog.

Is CVE-1999-0874 in the CISA KEV catalog?

No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.

Is there a public exploit for CVE-1999-0874?

Public exploit code is available.

Is there a fix for CVE-1999-0874?

No fixed version is listed yet; check the vendor advisory for mitigations.

How urgently should CVE-1999-0874 be patched?

Brandefense priority: patch immediately, because it is very likely to be exploited soon.

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Vulnerability Intelligence

CVE-1999-0874

CriticalPublic exploit

Buffer overflow in IIS 4.0 allows remote attackers to cause a denial of service via a malformed request for files with .HTR, .IDC, or .STM extensions.

Published Jun 16, 1999 · Updated Apr 15, 2026

Key Facts

Patch immediately

CVE-1999-0874 is a critical-severity vulnerability (CVSS 10.0 v2) affecting Internet Information Server (Microsoft), Windows 2000 (Microsoft), Windows Nt (Microsoft).
It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
EPSS estimates a 75% 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

10.0

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

EPSS (30-day exploit likelihood)

75%

Higher than 99.4% 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-1999-0874 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

Description

Buffer overflow in IIS 4.0 allows remote attackers to cause a denial of service via a malformed request for files with .HTR, .IDC, or .STM extensions.

Affected Products

4 affected entries in total

Product	Affected versions	Fixed in
Internet Information ServerMicrosoft	4.0	n/a
Windows 2000Microsoft	See advisory	n/a
Windows NtMicrosoft	4.0	n/a

Timeline

Publicly disclosed
Jun 16, 1999
Last updated
Apr 15, 2026

Weakness Type

CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

6 more references in the full CVE brief

FAQ

Common Questions.

Buffer overflow in IIS 4.0 allows remote attackers to cause a denial of service via a malformed request for files with .HTR, .IDC, or .STM extensions.
Affected: Internet Information Server (Microsoft) versions 4.0; Windows 2000 (Microsoft); Windows Nt (Microsoft) versions 4.0. 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-1999-0874 Running On Your Attack Surface?

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