What’s Vulnerable › Vulnerabilities

CVE-2020-1476: ASP.NET and .NET Elevation of Privilege Vulnerability

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-08-17 · updated 2026-06-17

Description

An elevation of privilege vulnerability exists when ASP.NET or .NET web applications running on IIS improperly allow access to cached files. An attacker who successfully exploited this vulnerability could gain access to restricted files. To exploit this vulnerability, an attacker would need to send a specially crafted request to an affected server. The update addresses the vulnerability by changing how ASP.NET and .NET handle requests.

Affected products

• Microsoft .NET Framework: 2.0-sp2, 3.5, 4.6.2, 4.7, 4.7.1, 4.7.2 (+5)
• Microsoft .NET Framework 2.0 Service Pack 2: from 2.0.0 before publication — fixed in publication
• Microsoft .NET Framework 3.5: from 3.5.0 before publication — fixed in publication
• Microsoft .NET Framework 3.5.1: from 3.5.0 before publication — fixed in publication
• Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2: from 3.0.0.0 before publication — fixed in publication
• Microsoft .NET Framework 3.5 AND 4.6/4.6.1/4.6.2: from 3.5.0 before publication — fixed in publication
• Microsoft .NET Framework 3.5 AND 4.7.1/4.7.2: from 3.0 before publication — fixed in publication
• Microsoft .NET Framework 3.5 AND 4.7.2: from 4.7.0 before publication — fixed in publication
• Microsoft .NET Framework 3.5 AND 4.8: from 4.8.0 before publication — fixed in publication
• Microsoft .NET Framework 4.5.2: from 4.0.0.0 before publication — fixed in publication
• Microsoft .NET Framework 4.6: from 4.0.0.0 before publication — fixed in publication
• Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2: from 4.0.0.0 before publication — fixed in publication
• Microsoft .NET Framework 4.8: from 4.8.0 before publication — fixed in publication

How to fix

Upgrade to a fixed version: Microsoft .NET Framework 2.0 Service Pack 2 publication; Microsoft .NET Framework 3.5 publication; Microsoft .NET Framework 3.5.1 publication; Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 publication; Microsoft .NET Framework 3.5 AND 4.6/4.6.1/4.6.2 publication; Microsoft .NET Framework 3.5 AND 4.7.1/4.7.2 publication; Microsoft .NET Framework 3.5 AND 4.7.2 publication; Microsoft .NET Framework 3.5 AND 4.8 publication; Microsoft .NET Framework 4.5.2 publication; Microsoft .NET Framework 4.6 publication; Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 publication; Microsoft .NET Framework 4.8 publication. Check the vendor advisory for mitigations.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1476
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1476

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