Which products and versions are affected by CVE-2001-0500?

Affected: Indexing Service (Microsoft); Index Server (Microsoft) versions 2.0; Internet Information Server (Microsoft). The full list is in the CVE brief.

Is CVE-2001-0500 being exploited in the wild?

It is exploited in the wild, listed in Industry KEV feed since Jul 19, 2001.

Is CVE-2001-0500 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-2001-0500?

Public exploit code is available.

Is there a fix for CVE-2001-0500?

Fixed versions are available, including Internet Information Server 6.0.

How urgently should CVE-2001-0500 be patched?

Brandefense priority: patch immediately, because it is listed as exploited in the wild.

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Vulnerability Intelligence

CVE-2001-0500

CriticalExploitedPublic exploit

Buffer overflow in ISAPI extension (idq.dll) in Index Server 2.0 and Indexing Service 2000 in IIS 6.0 beta and earlier allows remote attackers to execute arbitrary commands via a long argument to Internet Data Administration (.ida) and Internet Data Query (.idq) files such as…

Published Jul 21, 2001 · Updated Apr 15, 2026

Key Facts

Patch immediately

CVE-2001-0500 is a critical-severity vulnerability (CVSS 10.0 v2) affecting Indexing Service (Microsoft), Index Server (Microsoft), Internet Information Server (Microsoft).
It is exploited in the wild, listed in Industry KEV feed since Jul 19, 2001. Public exploit code is available.
EPSS estimates a 97% probability of exploitation in the next 30 days.
Fixed versions are available, including Internet Information Server 6.0.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v2

10.0

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

EPSS (30-day exploit likelihood)

97%

Higher than 99.8% of all scored CVEs

Exploited in the wild

Yes

1 catalog listing

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2001-0500 brief as a PDF

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

Description

Known-Exploited Catalog Listings

Catalog	Added	Remediation due	Ransomware use
Industry KEV feed	Jul 19, 2001	n/a	Not reported

Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Affected Products

3 affected entries in total

Product	Affected versions	Fixed in
Indexing ServiceMicrosoft	See advisory	n/a
Index ServerMicrosoft	2.0	n/a
Internet Information ServerMicrosoft	See advisory	6.0

Patched Releases

Internet Information Server

6.0

Timeline

Added to Industry KEV feed
Jul 19, 2001
Publicly disclosed
Jul 21, 2001
Last updated
Apr 15, 2026

References

11 more references in the full CVE brief

FAQ

Common Questions.

Buffer overflow in ISAPI extension (idq.dll) in Index Server 2.0 and Indexing Service 2000 in IIS 6.0 beta and earlier allows remote attackers to execute arbitrary commands via a long argument to Internet Data Administration (.ida) and Internet Data Query (.idq) files such as default.ida, as commonly exploited by Code…
Affected: Indexing Service (Microsoft); Index Server (Microsoft) versions 2.0; Internet Information Server (Microsoft). The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Jul 19, 2001.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Internet Information Server 6.0.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.

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