{"cve":"CVE-2011-1271","nvd":{"published":"2011-05-10T19:55:02.027","modified":"2026-06-16T23:29:03.520","status":"Modified","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.\"","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L","score":7.7},"cwes":["CWE-264","CWE-476"],"references":["http://stackoverflow.com/questions/2135509/bug-only-occurring-when-compile-optimization-enabled/","https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-044","https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12686","http://stackoverflow.com/questions/2135509/bug-only-occurring-when-compile-optimization-enabled/","https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-044"],"products":["microsoft:.net_framework"],"source":"nvd","synced_at":"2026-10-19T19:58:50.521460154+00:00"},"epss":{"cve":"CVE-2011-1271","score":0.20096,"percentile":0.9745,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}