All vulnerabilities

Servers and applications

CVE-2001-0004

IIS 5.0 and 4.0 allows remote attackers to read the source code for executable web server programs by appending "%3F+.htr" to the requested URL, which causes the files to be parsed by the .HTR ISAPI extension, aka a variant of the "File Fragment Reading via .HTR" vulnerability.

Severity
Medium 5.0
Published
12 Feb 2001
Last changed
16 Jun 2026
Added to UpHeron
21 Oct 2026
Exploit chance
28% in the next 30 daysHigher than 98% of CVEs. EPSS by FIRST, 12 Nov 2026
Attack
Over the network · No login needed
Attacker can
Read some data
CVSS vector
AV:N/AC:L/Au:N/C:P/I:N/A:N
Sources
NVD

Affected software

SoftwareAffected versions
Microsoft IISServers and applications · cpe:a:microsoft:internet_information_services
  • Version 5.0

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2001-0004
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2001-0004