{"id":"CVE-2011-1271","aliases":["EUVD-2011-1279","GHSA-w649-2qr9-fg6v"],"status":"published","title":"The JIT compiler in Microsoft .NET Framework 3.5 Gold and SP1, 3.5.1, and 4.0, when...","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.\"","severity":{"version":"2.0","score":5.1,"vector":"AV:N/AC:H/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-08","score":0.20096,"percentile":0.97467,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":false},"cwes":["CWE-264","CWE-476"],"published":"2011-05-10T19:00:00Z","modified":"2026-06-16T23:29:03Z","exploits":[{"source":"exploitdb","id":"EDB-35740","title":"Microsoft .NET Framework JIT Compiler - Optimization NULL String Remote Code Execution","type":"remote","platform":"windows","date":"2011-03-04","verified":true,"url":"https://www.exploit-db.com/exploits/35740"}],"products":[{"vendor":"microsoft","product":".net_framework"}],"references":[{"url":"https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12686","tags":["vdb-entry","signature","x_refsource_OVAL","x_transferred"]},{"url":"https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-044","tags":["vendor-advisory","x_refsource_MS","x_transferred"]},{"url":"http://stackoverflow.com/questions/2135509/bug-only-occurring-when-compile-optimization-enabled/","tags":["x_refsource_MISC","x_transferred","Exploit"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2011-1271"},{"url":"http://stackoverflow.com/questions/2135509/bug-only-occurring-when-compile-optimization-enabled"},{"url":"https://github.com/advisories/GHSA-w649-2qr9-fg6v"}],"sources":{"cve":[{"id":"CVE-2011-1271","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.\"","status":"published","published":"2011-05-10T19:00:00Z","modified":"2024-10-17T18:54:02.496Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L","level":"high","assessor":"adp"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T14:35:38.321377Z"}],"euvd":[{"id":"EUVD-2011-1279","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.\"","status":"published","published":"2011-05-10T19:00:00Z","modified":"2024-10-17T18:54:02Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L","level":"high"}],"updated_at":"2026-11-03T00:27:33.264541Z"}],"ghsa":[{"id":"GHSA-w649-2qr9-fg6v","title":"The JIT compiler in Microsoft .NET Framework 3.5 Gold and SP1, 3.5.1, and 4.0, when...","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.\"","status":"published","published":"2022-05-13T01:15:29Z","modified":"2024-10-17T21:32:31Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L","level":"high"}],"cwes":["CWE-476"],"updated_at":"2026-11-02T14:58:32.565259Z"}],"nvd":[{"id":"CVE-2011-1271","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.\"","status":"published","published":"2011-05-10T19:55:02.027Z","modified":"2026-06-16T23:29:03.52Z","cvss":[{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L","level":"high","assessor":"secondary"},{"version":"2.0","score":5.1,"vector":"AV:N/AC:H/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-264","CWE-476"],"updated_at":"2026-11-02T14:02:08.47516Z"}]}}