CVE-2004-0847

Exp

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."

Published: 2004-11-03 Last update: 2026-04-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2004-0847 is rated High Exploit Risk (83.4/100): CVSS Critical severity, with high exploitation likelihood (EPSS 52.83%, 98th percentile). 2 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2004-0847

EDB-ID Source Kind Published Link
24666 exploit_db edb 2004-10-06 Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2004-0847

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-12-28 64.44% 52.83% -11.61%
2 2025-12-27 52.83% 64.44% +11.61%
3 2025-11-01 — 52.83% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2004-0847

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2004-0847

Affected software / configurations for CVE-2004-0847

Vendor Product Version Raw CPE
microsoft asp.net <= 1.1 cpe:2.3:a:microsoft:asp.net:*:*:*:*:*:*:*:*
microsoft asp.net 1.1 cpe:2.3:a:microsoft:asp.net:1.1:sp1:*:*:*:*:*:*

References for CVE-2004-0847

URL Tags
http://archives.neohapsis.com/archives/ntbugtraq/2004-q3/0221.html Exploit Vendor Advisory
http://sourceforge.net/mailarchive/forum.php?thread_id=5671607&forum_id=24754 Broken Link
http://www.kb.cert.org/vuls/id/283646 Third Party Advisory US Government Resource
http://www.securityfocus.com/bid/11342 Third Party Advisory VDB Entry
http://www.us-cert.gov/cas/techalerts/TA05-039A.html Third Party Advisory US Government Resource
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2005/ms05-004
https://exchange.xforce.ibmcloud.com/vulnerabilities/17644 Third Party Advisory VDB Entry
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A3556 Third Party Advisory
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A4987 Third Party Advisory
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