ed0e1e4d44
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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Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=992
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In issue #757, I described multiple bugs related to the handling of DIBs (Device Independent Bitmaps) embedded in EMF records, as implemented in the user-mode Windows GDI library (gdi32.dll). As a quick reminder, the DIB-embedding records follow a common scheme: they include four fields, denoting the offsets and lengths of the DIB header and DIB data (named offBmiSrc, cbBmiSrc, offBitsSrc, cbBitsSrc). A correct implementation should verify that:
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1) cbBmiSrc is within expected bounds, accounting for the DIB header, color palette etc.
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2) the (offBmiSrc, offBmiSrc + cbBmiSrc) region resides within the record buffer's area.
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3) cbBitsSrc is within expected bounds, and especially that it is larger or equal the expected number of bitmap bytes.
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4) the (offBitsSrc, offBitsSrc + cbBitsSrc) region resides within the record buffer's area.
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In the previous bug, I listed various combinations of missing checks in at least 10 different records:
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- EMR_ALPHABLEND
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- EMR_BITBLT
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- EMR_MASKBLT
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- EMR_PLGBLT
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- EMR_STRETCHBLT
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- EMR_TRANSPARENTBLT
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- EMR_SETDIBITSTODEVICE
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- EMR_STRETCHDIBITS
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- EMR_CREATEMONOBRUSH
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- EMR_EXTCREATEPEN
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As part of MS16-074, some of the bugs were indeed fixed, such as the EMR_STRETCHBLT record, which the original proof-of-concept image relied on. However, we've discovered that not all of the DIB-related problems are gone. For instance, the implementation of EMR_SETDIBITSTODEVICE (residing in the MRSETDIBITSTODEVICE::bPlay function) still doesn't enforce condition #3. As a result, it is possible to disclose uninitialized or out-of-bounds heap bytes via pixel colors, in Internet Explorer and other GDI clients which allow the extraction of displayed image data back to the attacker.
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The proof-of-concept file attached here consists of a single EMR_SETDIBITSTODEVICE record (excluding the header/EOF records), which originally contained a 1x1 bitmap. The dimensions of the DIB were then manually altered to 16x16, without adding any more actual image data. As a consequence, the 16x16/24bpp bitmap is now described by just 4 bytes, which is good for only a single pixel. The remaining 255 pixels are drawn based on junk heap data, which may include sensitive information, such as private user data or information about the virtual address space. I have confirmed that the vulnerability reproduces both locally in Internet Explorer, and remotely in Office Online, via a .docx document containing the specially crafted EMF file.
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It is strongly advised to perform a careful audit of all EMF record handlers responsible for dealing with DIBs, in order to make sure that each of them correctly enforces all four conditions necessary to prevent invalid memory access (and subsequent memory disclosure) while processing the bitmaps.
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Proof of Concept:
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https://github.com/offensive-security/exploitdb-bin-sploits/raw/master/bin-sploits/41363.zip |