CVE-2001-0239Isa Server Vulnerability
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.
Published Jul 2, 2001 · Updated Apr 15, 2026
Key Facts
Patch immediately- CVE-2001-0239 is a high-severity vulnerability (CVSS 7.5 v2) affecting Isa Server (Microsoft).
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 28% 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 public exploit code exists for a high-severity flaw.
Scores
CVSS v2
7.5
AV:N/AC:L/Au:N/C:P/I:P/A:P
EPSS (30-day exploit likelihood)
28%
Higher than 98.0% of all scored CVEs
Exploit maturity
Proof of concept
ATLAS score
35/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Not listed
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Proof of concept
Public exploit code
1
Proof-of-concept links
In-the-wild evidence
2
Reports of active use
Advisories And Exploit References
Description
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.
Affected Products
1 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Isa ServerMicrosoft | 2000 | n/a |
Timeline
Publicly disclosed
Jul 2, 2001
Last updated
Apr 15, 2026
References
- advisory20010417 [SX-20010320-2b] - Followup re. Microsoft ISA Server Denial of Service
- patch2600
- exploitExploitDB-20763
- exploit20010416 [SX-20010320-2] - Microsoft ISA Server Denial of Service
- exploit20010427 Microsoft ISA Server Vulnerability
FAQ
Common Questions.
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.
Affected: Isa Server (Microsoft) versions 2000. 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 public exploit code exists for a high-severity flaw.
Is CVE-2001-0239 On Your Attack Surface?
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