Signature Detail
Short Name |
HTTP:IIS:MALFORMED-HTR-REQUEST |
|---|---|
Severity |
High |
Recommended |
No |
Recommended Action |
Drop |
Category |
HTTP |
Keywords |
IIS 4.0/5.0 Malformed .htr Request (AuthChangeUrl) |
Release Date |
2003/04/22 |
Update Number |
1213 |
Supported Platforms |
di-5.3+, idp-4.0+, isg-3.0+, j-series-9.5+, mx-9.4+, srx-9.2+, srx-branch-9.4+, vsrx-12.1+ |
HTTP: IIS 4.0/5.0 Malformed .htr Request (AuthChangeUrl)
This signature detects attempts to exploit a known vulnerability against Microsoft Internet Information Server (IIS). IIS versions 4.0 and 5.0 are vulnerable. Attackers can send malformed .htr requests that can cause a denial-of-service (DoS) condition.
Extended Description
The virtual directory within IIS 4.0 and 5.0 contains .htr files which permits users to change passwords remotely. If a user initiates a password change request containing malformed data, the server CPU becomes fully utilized until the administrator performs a reboot to regain normal functionality. The patch available for this issue creates a similar vulnerability which is exploited by appending %3F+.htr to a request.
Affected Products
- Microsoft IIS 4.0
- Microsoft IIS 4.0 Alpha
- Microsoft IIS 5.0
References
- BugTraq: 1191
- CVE: CVE-2000-0304
- URL: http://www.microsoft.com/technet/security/bulletin/ms00-031.mspx