Microsoft ISA Server 2000 Web Proxy denial of service

CVSS Meta Temp Score
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CTI Interest Score
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4.8$0-$5k0.00

Summaryinfo

A vulnerability was found in Microsoft ISA Server 2000. It has been classified as problematic. Affected is an unknown function of the component Web Proxy. Performing a manipulation results in denial of service. This vulnerability is reported as CVE-2001-0239. Moreover, an exploit is present. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Microsoft ISA Server 2000 (Firewall Software). It has been classified as problematic. This affects an unknown code block of the component Web Proxy. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. The summary by CVE is:

Microsoft Internet Security and Acceleration (ISA) Server 2000 Web Proxy allows remote attackers to cause a denial of service via a long web request with a specific type.

The weakness was disclosed 07/02/2001 with Microsoft as confirmed posting (Bugtraq). The advisory is shared at securityfocus.com. This vulnerability is uniquely identified as CVE-2001-0239. 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 are unknown but a public exploit is available.

A public exploit has been developed in ANSI C. The exploit is shared for download at securityfocus.com. It is declared as proof-of-concept. The commercial vulnerability scanner Qualys is able to test this issue with plugin 90124 (Web Request Can Cause Access Violation in Microsoft ISA Server 2000 Web Proxy Service (MS01-021)).

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at X-Force (6383), Exploit-DB (20763), SecurityFocus (BID 2600†) and Vulnerability Center (SBV-803†). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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: 4.8

VulDB Base Score: 5.3
VulDB Temp Score: 4.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔍
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Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Programming Language: 🔍
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Qualys ID: 🔍
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Exploit-DB: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
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Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

04/16/2001 🔍
04/16/2001 +0 days 🔍
07/02/2001 +77 days 🔍
07/02/2001 +0 days 🔍
02/04/2003 +582 days 🔍
07/04/2014 +4168 days 🔍
10/07/2025 +4113 days 🔍

Sourcesinfo

Vendor: microsoft.com

Advisory: securityfocus.com⛔
Organization: Microsoft
Status: Confirmed

CVE: CVE-2001-0239 (🔍)
GCVE (CVE): GCVE-0-2001-0239
GCVE (VulDB): GCVE-100-16917
X-Force: 6383 - Microsoft ISA Server Web Proxy denial of service
SecurityFocus: 2600 - Microsoft ISA Server Web Proxy DoS Vulnerability
Vulnerability Center: 803 - [MS01-021] DoS in Microsoft ISA Server 2000 Web Proxy via Long Web Requests with Specific Type, High

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

Entryinfo

Created: 07/05/2014 00:46
Updated: 10/07/2025 17:38
Changes: 07/05/2014 00:46 (65), 05/08/2019 20:32 (1), 01/30/2025 19:26 (22), 10/07/2025 17:38 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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