Microsoft ISA Server Web Proxy denial of service
| isa-web-proxy-dos (6383) |  Medium Risk |
Description:
Microsoft Internet Security and Acceleration (ISA) Server is vulnerable to a denial of service attack against the Web Proxy service. In versions of ISA with the Web Publishing feature enabled, a remote attacker can send an unusually long HTTP request to the Web Proxy service on port 80 to cause the service to fail. This results in preventing all incoming and outgoing Web traffic from passing through the firewall. The Web Proxy service must be restarted in order to regain normal functionality.
*CVSS:
| Base Score: | 3.5 |
| Access Vector: | Remote |
| Access Complexity: | Low |
| Authentication: | Not Required |
| Confidentiality Impact: | None |
| Integrity Impact: | None |
| Availability Impact: | Partial |
| Temporal Score: | 2.6 |
| Exploitability: | Unproven |
| Remediation Level: | Official-Fix |
| Report Confidence: | Confirmed |
Consequences:
Denial of Service
Remedy:
Apply the patch for this vulnerability, as listed in Microsoft Security Bulletin MS01-045. See References.
Note: Microsoft originally provided a patch for this vulnerability in MS01-021, but it was superseded by the patch released with MS01-045.
References:
- CIAC Information Bulletin L-073: Microsoft ISA Web Proxy Service Denial of Service.
- Microsoft Security Bulletin MS01-021: Web Request Can Cause Access Violation in ISA Server Web Proxy Service.
- Microsoft Security Bulletin MS01-045: ISA Server H.323 Gatekeeper Service Contains Memory Leak.
- SecureXpert Labs Advisory SX-20010320-2: Denial of Service in Microsoft ISA server v1.0.
- SecureXpert Labs Advisory SX-20010320-2b: Followup re. Microsoft ISA Server Denial of Service.
- BID-2600: Microsoft ISA Server Web Proxy DoS Vulnerability
- CVE-2001-0239: 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.
Platforms Affected:
- Microsoft ISA Server 2000
Reported:
Apr 16, 2001
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The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall IBM be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.