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Fencer Vulns
medium 5.0

CVE-2001-0004 json

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…

published 2001-02-12 25 y ago modified 2026-06-16 4 mo ago also EUVD-2001-0004

cvss
5.0
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
28.2%
EPSS 28.2% chance of exploitation in 30 days, percentile 98%
public exploits
0
none known

Summary

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.

Exploit prediction

28.21% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.