How severe is CVE-2004-0847?

CVE-2004-0847 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2004-0847 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 76% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2004-0847?

CVE-2004-0847 primarily affects Microsoft Asp.net. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2004-0847?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2004-0847 published?

CVE-2004-0847 was published on 2004-11-03 and last updated on 2026-06-16.

CVE-2004-0847

CVE-2004-0847 is a critical-severity vulnerability in Microsoft Asp.net with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 76% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-22.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 76% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-22
Affected product: Microsoft Asp.net
Published: 2004-11-03
Last modified: 2026-06-16

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."

Frequently asked questions

What is CVE-2004-0847?: 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."
How severe is CVE-2004-0847?: CVE-2004-0847 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2004-0847 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 76% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2004-0847?: CVE-2004-0847 primarily affects Microsoft Asp.net. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2004-0847?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2004-0847 published?: CVE-2004-0847 was published on 2004-11-03 and last updated on 2026-06-16.

References

Affected products (2)

cpe:2.3:a:microsoft:asp.net:*:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:asp.net:1.1:sp1:*:*:*:*:*:*

More vulnerabilities in Microsoft Asp.net

CVE-2006-1364 — High (CVSS 7.5): Microsoft w3wp (aka w3wp.exe) does not properly handle when the AspCompat directive is not used when referencing COM…
CVE-2003-0768 — Medium (CVSS 6.8): Microsoft ASP.Net 1.1 allows remote attackers to bypass the Cross-Site Scripting (XSS) and Script Injection protection…
CVE-2005-1664 — Medium (CVSS 6.4): The __VIEWSTATE functionality in Microsoft ASP.NET 1.x allows remote attackers to conduct replay attacks to (1) apply a…
CVE-2005-2224 — Medium (CVSS 5.0): aspnet_wp.exe in Microsoft ASP.NET web services allows remote attackers to cause a denial of service (CPU consumption…
CVE-2005-1665 — Medium (CVSS 5.0): The __VIEWSTATE functionality in Microsoft ASP.NET 1.x, when not cryptographically signed, allows remote attackers to…
CVE-2010-2088 — Medium (CVSS 4.3): ASP.NET in Microsoft .NET 3.5 does not properly handle an unencrypted view state, which allows remote attackers to…

All CVEs affecting Microsoft Asp.net →

Other CWE-22 (Path Traversal) vulnerabilities

CVE-2026-48282 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Limitation of a Pathname to a Restricted…
CVE-2026-54917 — Critical (CVSS 10.0): SeaweedFS is a distributed storage system for object storage (S3), file systems, and Iceberg tables. Prior to 4.30, the…
CVE-2026-11429 — Critical (CVSS 10.0): Two endpoints in the Vault Service ScriptsController, shared by Altium Enterprise Server and Altium 365, accept file…
CVE-2026-34909 — Critical (CVSS 10.0): A malicious actor with access to the network could exploit a Path Traversal vulnerability found in UniFi OS devices to…
CVE-2026-7411 — Critical (CVSS 10.0): In Eclipse BaSyx Java Server SDK versions prior to 2.0.0-milestone-10, inadequate path normalization in the Submodel…
CVE-2026-36767 — Critical (CVSS 10.0): A path traversal vulnerability in the /content/images/add endpoint of shopizer v3.2.5 allows attackers write arbitrary…

Browse all CWE-22 (Path Traversal) vulnerabilities →