CVE-2004-0847

Name: CVE-2004-0847
Creator: NVD / NIST
Published: 2004-11-03T05:00:00+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 75.70%

Last modified Jun 16, 2026

CVE-2004-0847 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. The Microsoft .NET forms authentication capability for ASP.NET allows remote attackers to bypass authentication for .aspx files in restricted directories via a request containing a (1) "\" (backslash) or (2) "%5C" (encoded backslash), aka "Path Validation Vulnerability.". EPSS estimates a 75.70% chance of exploitation in the next 30 days.

Description

The Microsoft .NET forms authentication capability for ASP.NET allows remote attackers to bypass authentication for .aspx files in restricted directories via a request containing a (1) "\" (backslash) or (2) "%5C" (encoded backslash), aka "Path Validation Vulnerability."

Metrics

CVSS 3.0

9.8/10

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

75.70%

99.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-22

Affected Software

Vendor	Product	Versions	Update
Microsoft	Asp.Net	<= 1.1	—
Microsoft	Asp.Net	1.1	Sp1

References

http://archives.neohapsis.com/archives/ntbugtraq/2004-q3/0221.htmlExploit, Vendor Advisory
http://sourceforge.net/mailarchive/forum.php?thread_id=5671607&forum_id=24754Broken Link
http://www.kb.cert.org/vuls/id/283646Third Party Advisory, US Government Resource
http://www.securityfocus.com/bid/11342Third Party Advisory, VDB Entry
http://www.us-cert.gov/cas/techalerts/TA05-039A.htmlThird Party Advisory, US Government Resource
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2005/ms05-004
https://exchange.xforce.ibmcloud.com/vulnerabilities/17644Third Party Advisory, VDB Entry
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A3556Third Party Advisory
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A4987Third Party Advisory
http://archives.neohapsis.com/archives/ntbugtraq/2004-q3/0221.htmlExploit, Vendor Advisory
http://sourceforge.net/mailarchive/forum.php?thread_id=5671607&forum_id=24754Broken Link
http://www.kb.cert.org/vuls/id/283646Third Party Advisory, US Government Resource
http://www.securityfocus.com/bid/11342Third Party Advisory, VDB Entry
http://www.us-cert.gov/cas/techalerts/TA05-039A.htmlThird Party Advisory, US Government Resource
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2005/ms05-004
https://exchange.xforce.ibmcloud.com/vulnerabilities/17644Third Party Advisory, VDB Entry
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A3556Third Party Advisory
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A4987Third Party Advisory

Timeline

Published: Nov 3, 2004
Last Modified: Jun 16, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2004-0847?

How severe is CVE-2004-0847?

CVE-2004-0847 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 75.70% probability of exploitation in the next 30 days.

How do I fix CVE-2004-0847?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2004-0847?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST