Microsoft IIS 4.0/5.0 URL File information disclosure

CVSS Meta Temp Score
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CTI Interest Score
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4.6$0-$5k0.00

Summaryinfo

A vulnerability was found in Microsoft IIS 4.0/5.0. It has been classified as critical. This vulnerability affects unknown code of the component URL Handler. Performing a manipulation with the input <url>%3F+.htr results in information disclosure (File). This vulnerability is identified as CVE-2001-0004. Additionally, an exploit exists. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability classified as critical has been found in Microsoft IIS 4.0/5.0 (Web Server). This affects an unknown code block of the component URL Handler. The manipulation with the input value <url>%3F+.htr leads to a information disclosure vulnerability (File). CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality. The summary by CVE is:

IIS 5.0 and 4.0 allows remote attackers to read the source code for executable web server programs by appending "%3F+.htr" to the requested URL, which causes the files to be parsed by the .HTR ISAPI extension, aka a variant of the "File Fragment Reading via .HTR" vulnerability.

The weakness was released 02/12/2001 with Microsoft as MS01-004 as confirmed bulletin (Technet). It is possible to read the advisory at microsoft.com. This vulnerability is uniquely identified as CVE-2001-0004. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details and a public exploit are known. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

It is declared as proof-of-concept. We expect the 0-day to have been worth approximately $5k-$25k. The commercial vulnerability scanner Qualys is able to test this issue with plugin 86102 (Microsoft IIS File Fragment Disclosure Vulnerability).

Applying the patch MS01-004 is able to eliminate this problem. The bugfix is ready for download at microsoft.com. Attack attempts may be identified with Snort ID 987.

The vulnerability is also documented in the databases at X-Force (5903), SecurityFocus (BID 2313†) and Vulnerability Center (SBV-3057†). Entry connected to this vulnerability is available at VDB-16369. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 4.6

VulDB Base Score: 5.3
VulDB Temp Score: 4.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Name: File
Class: Information disclosure / File
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Patch: MS01-004

Snort ID: 987
Snort Message: FILE-IDENTIFY .htr access file download request
Snort Class: 🔍
McAfee IPS: 🔍
McAfee IPS Version: 🔍

SourceFire IPS: 🔍

Timelineinfo

01/29/2001 🔍
02/12/2001 +14 days 🔍
02/12/2001 +0 days 🔍
02/12/2001 +0 days 🔍
12/01/2003 +1022 days 🔍
07/03/2014 +3867 days 🔍
10/11/2025 +4117 days 🔍

Sourcesinfo

Vendor: microsoft.com

Advisory: MS01-004
Organization: Microsoft
Status: Confirmed

CVE: CVE-2001-0004 (🔍)
GCVE (CVE): GCVE-0-2001-0004
GCVE (VulDB): GCVE-100-16371
X-Force: 5903 - Microsoft IIS 5.0 allows the viewing of files through malformed URL
SecurityFocus: 2313 - Microsoft IIS File Fragment Disclosure Vulnerability
Vulnerability Center: 3057 - [MS01-004] IIS 5.0 and 4.0 Source Code Disclosure, Medium

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍

Entryinfo

Created: 07/03/2014 10:23
Updated: 10/11/2025 01:04
Changes: 07/03/2014 10:23 (50), 05/17/2019 12:12 (27), 10/11/2025 01:04 (18)
Complete: 🔍
Cache ID: 216::103

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