HTTP: Malformed URL Request

This protocol anomaly triggers when it detects a malformed URL, such as a Unicode encoded field with non-hex digits or an encoded NULL byte.

Extended Description

Microsoft IIS 4.0 and 5.0 are both vulnerable to double dot "../" directory traversal exploitation if extended UNICODE character representations are used in substitution for "/" and "\". Unauthenticated users may access any known file in the context of the IUSR_machinename account. The IUSR_machinename account is a member of the Everyone and Users groups by default, therefore, any file on the same logical drive as any web-accessible file that is accessible to these groups can be deleted, modified, or executed. Successful exploitation would yield the same privileges as a user who could successfully log onto the system to a remote user possessing no credentials whatsoever. It has been discovered that a Windows 98 host running Microsoft Personal Web Server is also subject to this vulnerability. (March 18, 2001) This is the vulnerability exploited by the Code Blue Worm. **UPDATE**: It is believed that an aggressive worm may be in the wild that actively exploits this vulnerability.

Affected Products

Microsoft iis

Short Name
HTTP:REQERR:REQ-MALFORMED-URL
Severity
Minor
Recommended
False
Recommended Action
None
Category
HTTP
Keywords
CVE-2000-0884 CVE-2014-4158 IIS bid:1806 bid:68195 microsoft sans top20 unicode
Release Date
08/27/2003
Supported Platforms

srx-branch-12.3

srx-19.3

srx-branch-19.3

vsrx3bsd-19.2

srx-branch-19.4

vsrx-19.4

mx-12.3

mx-19.4

vmx-19.4

mx-19.3

vsrx3bsd-19.4

srx-19.4

vsrx-12.3

vmx-19.3

vsrx-19.2

srx-12.3

Sigpack Version
3689
False Positive
Rarely
Vendors

Microsoft

CVSS Score

7.5

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