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CVE-2011-1271

HIGHCVSS 7.7/10EPSS 20.10%

Last modified

CVE-2011-1271 is a high-severity vulnerability rated 7.7/10 on the CVSS scale. The JIT compiler in Microsoft .NET Framework 3.5 Gold and SP1, 3.5.1, and 4.0, when IsJITOptimizerDisabled is false, does not properly handle expressions related to null strings, which allows context-dependent attackers to bypass intended access restrictions, and consequently execute arbitrary code, in opportunistic circumstances by leveraging a crafted application, as demonstrated by (1) a crafted XAML browser application (aka XBAP), (2) a crafted ASP.NET application, or (3) a crafted .NET Framework application, aka ".NET Framework JIT Optimization Vulnerability.". EPSS estimates a 20.10% chance of exploitation in the next 30 days.

Description

The JIT compiler in Microsoft .NET Framework 3.5 Gold and SP1, 3.5.1, and 4.0, when IsJITOptimizerDisabled is false, does not properly handle expressions related to null strings, which allows context-dependent attackers to bypass intended access restrictions, and consequently execute arbitrary code, in opportunistic circumstances by leveraging a crafted application, as demonstrated by (1) a crafted XAML browser application (aka XBAP), (2) a crafted ASP.NET application, or (3) a crafted .NET Framework application, aka ".NET Framework JIT Optimization Vulnerability."

Metrics

CVSS 3.1
7.7/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L

EPSS Probability
20.10%

97.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
Microsoft.Net Framework4.0—
Microsoft.Net Framework3.5.1—
Microsoft.Net Framework2.0Sp2
Microsoft.Net Framework3.5Sp1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2011-1271?
The JIT compiler in Microsoft .NET Framework 3.5 Gold and SP1, 3.5.1, and 4.0, when IsJITOptimizerDisabled is false, does not properly handle expressions related to null strings, which allows context-dependent attackers to bypass intended access restrictions, and consequently execute arbitrary code, in opportunistic circumstances by leveraging a crafted application, as demonstrated by (1) a crafted XAML browser application (aka XBAP), (2) a crafted ASP.NET application, or (3) a crafted .NET Framework application, aka ".NET Framework JIT Optimization Vulnerability."
How severe is CVE-2011-1271?
CVE-2011-1271 has a CVSS score of 7.7/10 (HIGH severity). The EPSS model estimates a 20.10% probability of exploitation in the next 30 days.
How do I fix CVE-2011-1271?
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-2011-1271?

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

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Source: NVD / NIST