Microsoft IIS 4.0/5.0 URL input validation

CVSS Meta Temp Score
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CTI Interest Score
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7.3$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as problematic, was found in Microsoft IIS 4.0/5.0. Affected by this vulnerability is an unknown functionality of the component URL Handler. The manipulation results in input validation. This vulnerability is cataloged as CVE-2000-0258. The attack may be launched remotely. There is no exploit available. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability classified as critical has been found in Microsoft IIS 4.0/5.0 (Web Server). Affected is some unknown functionality of the component URL Handler. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on availability. CVE summarizes:

IIS 4.0 and 5.0 allows remote attackers to cause a denial of service by sending many URLs with a large number of escaped characters, aka the "Myriad Escaped Characters" Vulnerability.

The weakness was shared 04/12/2000 by Vanja Hrustic with Microsoft as MS00-023 as confirmed bulletin (Technet). The advisory is shared for download at microsoft.com. This vulnerability is traded as CVE-2000-0258. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available.

The commercial vulnerability scanner Qualys is able to test this issue with plugin 86139 (Microsoft IIS 4.0/5.0 Escaped Characters Vulnerability (MS00-023)).

Applying the patch MS00-023 is able to eliminate this problem. The bugfix is ready for download at microsoft.com.

The vulnerability is also documented in the databases at SecurityFocus (BID 1101†) and Vulnerability Center (SBV-780†). Once again VulDB remains the best source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.3

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

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: MS00-023

Timelineinfo

04/12/2000 🔍
04/12/2000 +0 days 🔍
04/12/2000 +0 days 🔍
04/12/2000 +0 days 🔍
02/03/2003 +1027 days 🔍
06/24/2014 +4159 days 🔍
04/21/2026 +4319 days 🔍

Sourcesinfo

Vendor: microsoft.com

Advisory: MS00-023
Researcher: Vanja Hrustic
Organization: Microsoft
Status: Confirmed

CVE: CVE-2000-0258 (🔍)
GCVE (CVE): GCVE-0-2000-0258
GCVE (VulDB): GCVE-100-15444
SecurityFocus: 1101 - Microsoft IIS 4.0/5.0 Escaped Characters Vulnerability
Vulnerability Center: 780 - [MS00-023] Microsoft IIS 4.0/5.0 Escaped Characters Vulnerability, High

Entryinfo

Created: 06/24/2014 11:07
Updated: 04/21/2026 04:02
Changes: 06/24/2014 11:07 (62), 05/08/2019 17:24 (10), 10/17/2025 19:34 (19), 04/21/2026 04:02 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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