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1979 changes to exploits/shellcodes Couchdb 1.5.0 - 'uuids' Denial of Service Apache CouchDB 1.5.0 - 'uuids' Denial of Service Beyond Remote 2.2.5.3 - Denial of Service (PoC) udisks2 2.8.0 - Denial of Service (PoC) Termite 3.4 - Denial of Service (PoC) SoftX FTP Client 3.3 - Denial of Service (PoC) Silverstripe 2.3.5 - Cross-Site Request Forgery / Open redirection SilverStripe CMS 2.3.5 - Cross-Site Request Forgery / Open Redirection Silverstripe CMS 3.0.2 - Multiple Vulnerabilities SilverStripe CMS 3.0.2 - Multiple Vulnerabilities Silverstripe CMS 2.4 - File Renaming Security Bypass SilverStripe CMS 2.4 - File Renaming Security Bypass Silverstripe CMS 2.4.5 - Multiple Cross-Site Scripting Vulnerabilities SilverStripe CMS 2.4.5 - Multiple Cross-Site Scripting Vulnerabilities Silverstripe CMS 2.4.7 - 'install.php' PHP Code Injection SilverStripe CMS 2.4.7 - 'install.php' PHP Code Injection Silverstripe Pixlr Image Editor - 'upload.php' Arbitrary File Upload SilverStripe CMS Pixlr Image Editor - 'upload.php' Arbitrary File Upload Silverstripe CMS 2.4.x - 'BackURL' Open Redirection SilverStripe CMS 2.4.x - 'BackURL' Open Redirection Silverstripe CMS - 'MemberLoginForm.php' Information Disclosure SilverStripe CMS - 'MemberLoginForm.php' Information Disclosure Silverstripe CMS - Multiple HTML Injection Vulnerabilities SilverStripe CMS - Multiple HTML Injection Vulnerabilities Apache CouchDB 1.7.0 and 2.x before 2.1.1 - Remote Privilege Escalation Apache CouchDB 1.7.0 / 2.x < 2.1.1 - Remote Privilege Escalation Monstra CMS before 3.0.4 - Cross-Site Scripting Monstra CMS < 3.0.4 - Cross-Site Scripting (2) Monstra CMS < 3.0.4 - Cross-Site Scripting Monstra CMS < 3.0.4 - Cross-Site Scripting (1) Navigate CMS 2.8 - Cross-Site Scripting Collectric CMU 1.0 - 'lang' SQL injection Joomla! Component CW Article Attachments 1.0.6 - 'id' SQL Injection LG SuperSign EZ CMS 2.5 - Remote Code Execution MyBB Visual Editor 1.8.18 - Cross-Site Scripting Joomla! Component AMGallery 1.2.3 - 'filter_category_id' SQL Injection Joomla! Component Micro Deal Factory 2.4.0 - 'id' SQL Injection RICOH Aficio MP 301 Printer - Cross-Site Scripting Joomla! Component Auction Factory 4.5.5 - 'filter_order' SQL Injection RICOH MP C6003 Printer - Cross-Site Scripting Linux/ARM - Egghunter (PWN!) + execve(_/bin/sh__ NULL_ NULL) Shellcode (28 Bytes) Linux/ARM - sigaction() Based Egghunter (PWN!) + execve(_/bin/sh__ NULL_ NULL) Shellcode (52 Bytes)
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2.7 KiB
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2.7 KiB
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Windows: NtImpersonateAnonymousToken AC to Non-AC EoP
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Platform: Windows 10 1703 and 1709
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Class: Elevation of Privilege
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Summary:
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The check for an AC token when impersonating the anonymous token doesn’t check impersonation token’s security level leading to impersonating a non-AC anonymous token leading to EoP.
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Description:
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There's a missing check for impersonation level in NtImpersonateAnonymousToken when considering if the caller is currently an AC. This results in the function falling into the restricted token case if the caller is impersonating a non AC token at identification or below. Some example code is shown highlighting the issue.
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SeCaptureSubjectContext(&ctx);
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PACCESS_TOKEN token = ctx.ClientToken;
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if (!ctx.ClientToken) <--- Should check the token's impersonation level here, and fallback to the PrimaryToken.
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token = ctx.PrimaryToken;
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if (token->Flags & 0x4000) {
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// ... Impersonate AC anonymous token.
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} else if (!SeTokenIsRestricted(PsReferencePrimaryToken())) { <-- AC PrimaryToken isn't restricted so this check passes
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// ... Impersonate normal anonymous token.
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}
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For example when using a split-token admin you can trivially get the linked token and impersonate that. As an AC token isn't restricted this results in impersonating the normal anonymous token which is arguably less restricted than the AC token in some cases and is certainly less restricted than the anonymous AC token which is normally created using SepGetAnonymousToken. For example you can open objects with a NULL DACL if you can traverse to them or open devices which would normally need the special AC device object flag for traversal across the object namespace. You can also access the anonymous token's device map and modify it, potentially leading to bypass of symbolic link protections in certain cases.
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Proof of Concept:
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I’ve provided a PoC as a C# project. The PoC will respawn itself as the Microsoft Edge AC and then execute the exploit. You must run this as a UAC split token admin. Note that this ISN’T a UAC bypass, just that a split-token admin has a trivial way of getting a non-AC token by requesting the linked token.
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1) Compile the C# project. It will need to grab the NtApiDotNet from NuGet to work. Ensure the main executable and DLLs are in a user writable location (this is needed to tweak the file permissions for AC).
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2) Execute the PoC as normal user level split-token admin.
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3) Once complete a dialog should appear indicating the operation is a success.
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Expected Result:
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The AC anonymous token is impersonated, or at least an error occurs.
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Observed Result:
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The Non-AC anonymous token is impersonated.
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Proof of Concept:
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https://github.com/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/43515.zip |