Vulnerabilities > CVE-2017-2806 - Out-of-bounds Read vulnerability in Lexmark Perceptive Document Filters 11.3.0.2228/11.3.0.2400
Attack vector
NETWORK Attack complexity
MEDIUM Privileges required
NONE Confidentiality impact
PARTIAL Integrity impact
NONE Availability impact
NONE Summary
An exploitable arbitrary read exists in the XLS parsing of the Lexmark Perspective Document Filters conversion functionality. A crafted XLS document can lead to a arbitrary read resulting in memory disclosure. The vulnerability was confirmed on versions 11.3.0.2228 and 11.3.0.2400
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 2 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Overread Buffers An adversary attacks a target by providing input that causes an application to read beyond the boundary of a defined buffer. This typically occurs when a value influencing where to start or stop reading is set to reflect positions outside of the valid memory location of the buffer. This type of attack may result in exposure of sensitive information, a system crash, or arbitrary code execution.
Seebug
| bulletinFamily | exploit |
| description | ### Summary An exploitable arbitrary read exists in the XLS parsing of the Lexmark Perspective Document Filters conversion functionality. A crafted XLS document can lead to a arbitrary read resulting in memory disclosure. The vulnerability was confirmed on versions 11.3.0.2228 and 11.3.0.2400 ### Tested Versions Lexmark Perceptive Document Filters 11.3.0.2228 Lexmark Perceptive Document Filters 11.3.0.2400 ### Product URLs http://www.lexmark.com/en_us/partners/enterprise-software/technology-partners/oem-technologies/document-filters.html ### CVSSv3 Score 4.3 - CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N ### CWE CWE-125 - Out-of-bounds Read ### Details This vulnerability is present in the Lexmark Document filter parsing which is used for big data, eDiscovery, DLP, email archival, content management, business intelligence and intelligent capture services. This product is mainly used by MarkLogic for document conversions as part of their web based document search and rendering. It can convert common formats such as Microsoft's document formats into more useable and easily viewed formats. There is a vulnerability in the parsing and conversion of XLS documents. A specially crafted XLS file can lead to an arbitrary read and ultimately memory disclosure. Let's investigate this vulnerability. After the Lexmark library attempts to read metadata from the malicious file, we see the following state: ``` Program received signal SIGSEGV, Segmentation fault. 0x00007ffff3818fdb in intermediate::Office::extract4BytesFromStringIt(char const**) () from ./libISYSreadershd.so (gdb) peda_active gdb-peda$ context [----------------------------------registers-----------------------------------] RAX: 0x3133701 RBX: 0x6ac3d0 --> 0x7ffff3f21210 --> 0x7ffff385c3f0 (<intermediate::Office::ShapeHLink::~ShapeHLink()>: mov QWORD PTR [rsp-0x8],rbp) RCX: 0x3133700 RDX: 0x3133702 RSI: 0xa80000 RDI: 0x7ffffffecfd8 --> 0x3133700 RBP: 0x6ac458 --> 0xaaefbeadde000002 RSP: 0x7ffffffecfa8 --> 0x7ffff38310df (cdqe) RIP: 0x7ffff3818fdb (movzx r8d,BYTE PTR [rcx]) R8 : 0x9c R9 : 0x7ffff69417b8 --> 0x6b7b80 --> 0x0 R10: 0x6c00000067 ('g') R11: 0x7ffff670a550 --> 0xfffcb240fffcabbe R12: 0xffad R13: 0x696fc0 --> 0x7ffff3f0b4f0 --> 0x7ffff35fb9c0 (<reader::excel97_2003::Sheet::~Sheet()>: mov QWORD PTR [rsp-0x10],rbp) R14: 0x6ac3d0 --> 0x7ffff3f21210 --> 0x7ffff385c3f0 (<intermediate::Office::ShapeHLink::~ShapeHLink()>: mov QWORD PTR [rsp-0x8],rbp) R15: 0x7ffff79c23f8 --> 0x0 EFLAGS: 0x10206 (carry PARITY adjust zero sign trap INTERRUPT direction overflow) [-------------------------------------code-------------------------------------] 0x7ffff3818fd0 <intermediate::Office::extract4BytesFromStringIt(char const**)>: mov rcx,QWORD PTR [rdi] 0x7ffff3818fd3: lea rax,[rcx+0x1] 0x7ffff3818fd7: lea rdx,[rcx+0x2] => 0x7ffff3818fdb: movzx r8d,BYTE PTR [rcx] 0x7ffff3818fdf: mov QWORD PTR [rdi],rax 0x7ffff3818fe2: movzx eax,BYTE PTR [rcx+0x1] 0x7ffff3818fe6: mov QWORD PTR [rdi],rdx 0x7ffff3818fe9: lea rdx,[rcx+0x3] [------------------------------------stack-------------------------------------] 0000| 0x7ffffffecfa8 --> 0x7ffff38310df (cdqe) 0008| 0x7ffffffecfb0 --> 0x7ffffffecff0 --> 0x6a9e00 --> 0x7ffff3f09010 --> 0x7ffff352edf0 (<common::IRenderable::SetZIndex(int)>: mov DWORD PTR [rdi+0x8],esi) 0016| 0x7ffffffecfb8 --> 0x20 (' ') 0024| 0x7ffffffecfc0 --> 0x20 (' ') 0032| 0x7ffffffecfc8 --> 0x6ac3e8 --> 0x7ffff79c23f8 --> 0x0 0040| 0x7ffffffecfd0 --> 0x696fc0 --> 0x7ffff3f0b4f0 --> 0x7ffff35fb9c0 (<reader::excel97_2003::Sheet::~Sheet()>: mov QWORD PTR [rsp-0x10],rbp) 0048| 0x7ffffffecfd8 --> 0x3133700 0056| 0x7ffffffecfe0 --> 0x6a9e00 --> 0x7ffff3f09010 --> 0x7ffff352edf0 (<common::IRenderable::SetZIndex(int)>: mov DWORD PTR [rdi+0x8],esi) [------------------------------------------------------------------------------] Legend: code, data, rodata, value Stopped reason: SIGSEGV gdb-peda$ bt #0 0x00007ffff3818fdb in intermediate::Office::extract4BytesFromStringIt(char const**) () from ./libISYSreadershd.so #1 0x00007ffff38310df in intermediate::Office::ShapeHLink::ShapeHLink(std::string const&) () from ./libISYSreadershd.so #2 0x00007ffff35f0497 in reader::excel97_2003::Sheet::parseImageObject(intermediate::common::ExcelDrawing*, reader::escher::MsofbtSpContainer*) () from ./libISYSreadershd.so #3 0x00007ffff35f1224 in reader::excel97_2003::Sheet::parseDrawingObjects(intermediate::common::ExcelDrawing*, reader::escher::MsofbtSpContainer*, std::_List_const_iterator<reader::excel97_2003::BiffTxo*>*, std::_List_const_iterator<reader::excel97_2003::BiffTxo*>) () from ./libISYSreadershd.so #4 0x00007ffff35f141e in reader::excel97_2003::Sheet::parseObject(intermediate::common::ExcelDrawing*, reader::escher::IMsoObject*, std::_List_const_iterator<reader::excel97_2003::BiffTxo*>*, std::_List_const_iterator<reader::excel97_2003::BiffTxo*>) () from ./libISYSreadershd.so #5 0x00007ffff35f2c7c in reader::excel97_2003::Sheet::Commit(ISYS_NS::CDataReader&) () from ./libISYSreadershd.so #6 0x00007ffff357ff52 in reader::excel97_2003::Workbook::Workbook(ISYS_NS::CStream*, IStorage*, wchar_t const*, bool) () from ./libISYSreadershd.so #7 0x00007ffff399adca in ISYS_NS::LibraryHD::CDocument::openExcel(ISYS_NS::CStream*, IStorage*, bool) () from ./libISYSreadershd.so #8 0x00007ffff399c2cf in ISYS_NS::LibraryHD::CDocument::open(IGR_Stream*, int, wchar_t const*) () from ./libISYSreadershd.so #9 0x00007ffff3994d4a in ISYS_NS::LibraryHD::IGR_HDAPI_Open(IGR_Stream*, int, wchar_t const*, void**, wchar_t*) () from ./libISYSreadershd.so #10 0x00007ffff61a22cb in ?? () from ./libISYSreaders.so #11 0x00007ffff61a6307 in ?? () from ./libISYSreaders.so #12 0x00007ffff7bcdb1b in IGR_Open_Stream_Ex () from ./libISYS11df.so #13 0x00000000004091e0 in processStream(IGR_Stream*, long long&, ToXHTML&, std::basic_ostringstream<char, std::char_traits<char>, std::allocator<char> >&) () #14 0x000000000040ab7b in processFile(std::string, std::basic_ostringstream<char, std::char_traits<char>, std::allocator<char> >&) () #15 0x000000000040b7a0 in main () #16 0x00007ffff65a4f45 in __libc_start_main (main=0x40b0b0 <main>, argc=0x2, argv=0x7fffffffdf58, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffdf48) at libc-start.c:287 #17 0x00000000004089e9 in _start () ``` As we can see in the function `extract4BytesFromStringIt` an access violation occurred during a read from a very specific address `rcx == 0x3133700`. The address from where these 4 bytes are extracted are fully controlled by attacker. Let's look at where this value comes from. We return to the place where rcx was set: ``` gdb-peda$ [----------------------------------registers-----------------------------------] RAX: 0x2a8729c RBX: 0x6ac3d0 --> 0x7ffff3f21210 --> 0x7ffff385c3f0 (<intermediate::Office::ShapeHLink::~ShapeHLink()>: mov QWORD PTR [rsp-0x8],rbp) RCX: 0x6ac464 --> 0xd3d3d3d3d3d3d3d3 RDX: 0x2000000 RSI: 0xa80000 RDI: 0x7ffffffecfd8 --> 0x6ac464 --> 0xd3d3d3d3d3d3d3d3 RBP: 0x6ac458 --> 0xaaefbeadde000002 RSP: 0x7ffffffecfb0 --> 0x7ffffffecff0 --> 0x6a9e00 --> 0x7ffff3f09010 --> 0x7ffff352edf0 (<common::IRenderable::SetZIndex(int)>: mov DWORD PTR [rdi+0x8],esi) RIP: 0x7ffff383125f (add QWORD PTR [rsp+0x28],rax) R8 : 0x9c R9 : 0x7ffff69417b8 --> 0x6b7b80 --> 0x0 R10: 0x6c00000067 ('g') R11: 0x7ffff670a550 --> 0xfffcb240fffcabbe R12: 0xffad R13: 0x696fc0 --> 0x7ffff3f0b4f0 --> 0x7ffff35fb9c0 (<reader::excel97_2003::Sheet::~Sheet()>: mov QWORD PTR [rsp-0x10],rbp) R14: 0x6ac3d0 --> 0x7ffff3f21210 --> 0x7ffff385c3f0 (<intermediate::Office::ShapeHLink::~ShapeHLink()>: mov QWORD PTR [rsp-0x8],rbp) R15: 0x7ffff79c23f8 --> 0x0 EFLAGS: 0x206 (carry PARITY adjust zero sign trap INTERRUPT direction overflow) [-------------------------------------code-------------------------------------] 0x7ffff3831253: lea rdi,[rsp+0x28] 0x7ffff3831258: call 0x7ffff34f2178 <intermediate::Office::extract4BytesFromStringIt(char const**)@plt> 0x7ffff383125d: cdqe => 0x7ffff383125f: add QWORD PTR [rsp+0x28],rax 0x7ffff3831264: jmp 0x7ffff38310c6 0x7ffff3831269: lea rdi,[rsp+0x28] 0x7ffff383126e: call 0x7ffff34f2178 <intermediate::Office::extract4BytesFromStringIt(char const**)@plt> 0x7ffff3831273: mov rbx,QWORD PTR [rsp+0x28] gdb-peda$ telescope $rsp+0x28 1 0000| 0x7ffffffecfd8 --> 0x6ac464 --> 0xd3d3d3d3d3d3d3d3 gdb-peda$ ni gdb-peda$ telescope $rsp+0x28 1 0000| 0x7ffffffecfd8 --> 0x3133700 ``` looking in the file for value the `0x2a8729c` we can find it at offset 0x6D82. It points to data inside the `complexData` field of the `OfficeArtRGFOPTE` record type (described in section 2.3.1.aspx) of the Office Drawing Binary File Format. Looking at the constructor name we can easily guess that the object which the currently library was parsing is related with a `hyperlink`. Indeed, it is wrongly parsing the `Hyperlink Object` structure (defined in section 2.3.7.1.aspx) of the Office Common Data Types and Objects Structures: The `Hyperlink object` has, among others, 2 string fields, dispalyName and targetFrameName. Both fields have variable lengths. The Perceptive Filter library reads the read string length from the file without extra checks and adds it to `displayName` pointer to find the location of `targetFrameName`. This lack of value sanitization leads to an arbitrary memory read and can result in memory disclosure. ### Crash Information ``` Program received signal SIGSEGV, Segmentation fault. [----------------------------------registers-----------------------------------] RAX: 0x3133701 RBX: 0x6ac3d0 --> 0x7ffff3f21210 --> 0x7ffff385c3f0 (<intermediate::Office::ShapeHLink::~ShapeHLink()>: mov QWORD PTR [rsp-0x8],rbp) RCX: 0x3133700 RDX: 0x3133702 RSI: 0xa80000 RDI: 0x7ffffffecfd8 --> 0x3133700 RBP: 0x6ac458 --> 0xaaefbeadde000002 RSP: 0x7ffffffecfa8 --> 0x7ffff38310df (cdqe) RIP: 0x7ffff3818fdb (movzx r8d,BYTE PTR [rcx]) R8 : 0x9c R9 : 0x7ffff69417b8 --> 0x6b7b80 --> 0x0 R10: 0x6c00000067 ('g') R11: 0x7ffff670a550 --> 0xfffcb240fffcabbe R12: 0xffad R13: 0x696fc0 --> 0x7ffff3f0b4f0 --> 0x7ffff35fb9c0 (<reader::excel97_2003::Sheet::~Sheet()>: mov QWORD PTR [rsp-0x10],rbp) R14: 0x6ac3d0 --> 0x7ffff3f21210 --> 0x7ffff385c3f0 (<intermediate::Office::ShapeHLink::~ShapeHLink()>: mov QWORD PTR [rsp-0x8],rbp) R15: 0x7ffff79c23f8 --> 0x0 EFLAGS: 0x10206 (carry PARITY adjust zero sign trap INTERRUPT direction overflow) [-------------------------------------code-------------------------------------] 0x7ffff3818fd0 <intermediate::Office::extract4BytesFromStringIt(char const**)>: mov rcx,QWORD PTR [rdi] 0x7ffff3818fd3: lea rax,[rcx+0x1] 0x7ffff3818fd7: lea rdx,[rcx+0x2] => 0x7ffff3818fdb: movzx r8d,BYTE PTR [rcx] 0x7ffff3818fdf: mov QWORD PTR [rdi],rax 0x7ffff3818fe2: movzx eax,BYTE PTR [rcx+0x1] 0x7ffff3818fe6: mov QWORD PTR [rdi],rdx 0x7ffff3818fe9: lea rdx,[rcx+0x3] [------------------------------------stack-------------------------------------] 0000| 0x7ffffffecfa8 --> 0x7ffff38310df (cdqe) 0008| 0x7ffffffecfb0 --> 0x7ffffffecff0 --> 0x6a9e00 --> 0x7ffff3f09010 --> 0x7ffff352edf0 (<common::IRenderable::SetZIndex(int)>: mov DWORD PTR [rdi+0x8],esi) 0016| 0x7ffffffecfb8 --> 0x20 (' ') 0024| 0x7ffffffecfc0 --> 0x20 (' ') 0032| 0x7ffffffecfc8 --> 0x6ac3e8 --> 0x7ffff79c23f8 --> 0x0 0040| 0x7ffffffecfd0 --> 0x696fc0 --> 0x7ffff3f0b4f0 --> 0x7ffff35fb9c0 (<reader::excel97_2003::Sheet::~Sheet()>: mov QWORD PTR [rsp-0x10],rbp) 0048| 0x7ffffffecfd8 --> 0x3133700 0056| 0x7ffffffecfe0 --> 0x6a9e00 --> 0x7ffff3f09010 --> 0x7ffff352edf0 (<common::IRenderable::SetZIndex(int)>: mov DWORD PTR [rdi+0x8],esi) [------------------------------------------------------------------------------] Legend: code, data, rodata, value Stopped reason: SIGSEGV 0x00007ffff3818fdb in intermediate::Office::extract4BytesFromStringIt(char const**) () from ./libISYSreadershd.so gdb-peda$ exploitable -m Warning: machine string printing is deprecated and may be removed in a future release. EXCEPTION_FAULTING_ADDRESS:0x00000003133700 EXCEPTION_CODE:0xb FAULTING_INSTRUCTION:movzx r8d,BYTE PTR [rcx] MAJOR_HASH:435211badab532edaeeaf65b62cabc34 MINOR_HASH:dd8a6e134c95f47c9f18aac4b3c591c2 STACK_DEPTH:16 STACK_FRAME:/home/icewall/bugs/cvtisys_86/libISYSreadershd.so!intermediate::Office::extract4BytesFromStringIt(char const**)+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/libISYSreadershd.so!intermediate::Office::ShapeHLink::ShapeHLink(std::string const&)+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/libISYSreadershd.so!reader::excel97_2003::Sheet::parseImageObject(intermediate::common::ExcelDrawing*, reader::escher::MsofbtSpContainer*)+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/libISYSreadershd.so!reader::excel97_2003::Sheet::parseDrawingObjects(intermediate::common::ExcelDrawing*, reader::escher::MsofbtSpContainer*, std::_List_const_iterator<reader::excel97_2003::BiffTxo*>*, std::_List_const_iterator<reader::excel97_2003::BiffTxo*>)+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/libISYSreadershd.so!reader::excel97_2003::Sheet::parseObject(intermediate::common::ExcelDrawing*, reader::escher::IMsoObject*, std::_List_const_iterator<reader::excel97_2003::BiffTxo*>*, std::_List_const_iterator<reader::excel97_2003::BiffTxo*>)+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/libISYSreadershd.so!reader::excel97_2003::Sheet::Commit(ISYS_NS::CDataReader&)+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/libISYSreadershd.so!reader::excel97_2003::Workbook::Workbook(ISYS_NS::CStream*, IStorage*, wchar_t const*, bool)+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/libISYSreadershd.so!ISYS_NS::LibraryHD::CDocument::openExcel(ISYS_NS::CStream*, IStorage*, bool)+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/libISYSreadershd.so!ISYS_NS::LibraryHD::CDocument::open(IGR_Stream*, int, wchar_t const*)+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/libISYSreadershd.so!ISYS_NS::LibraryHD::IGR_HDAPI_Open(IGR_Stream*, int, wchar_t const*, void**, wchar_t*)+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/libISYSreaders.so+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/libISYSreaders.so+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/libISYS11df.so!IGR_Open_Stream_Ex+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/convert!processStream(IGR_Stream*, long long&, ToXHTML&, std::basic_ostringstream<char, std::char_traits<char>, std::allocator<char> >&)+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/convert!processFile(std::string, std::basic_ostringstream<char, std::char_traits<char>, std::allocator<char> >&)+0x0 STACK_FRAME:/home/icewall/bugs/cvtisys_86/convert!main+0x0 INSTRUCTION_ADDRESS:0x007ffff3818fdb INVOKING_STACK_FRAME:0 DESCRIPTION:Access violation on source operand SHORT_DESCRIPTION:SourceAv (26/29) OTHER_RULES:AccessViolation (28/29) CLASSIFICATION:UNKNOWN EXPLANATION:The target crashed on an access violation at an address matching the source operand of the current instruction. This likely indicates a read access violation. Description: Access violation on source operand Short description: SourceAv (26/29) Hash: 435211badab532edaeeaf65b62cabc34.dd8a6e134c95f47c9f18aac4b3c591c2 Exploitability Classification: UNKNOWN Explanation: The target crashed on an access violation at an address matching the source operand of the current instruction. This likely indicates a read access violation. Other tags: AccessViolation (28/29) ``` ### Timeline * 2017-04-05 - Vendor Disclosure * 2017-04-18 - Public Release ### CREDIT * Discovered by Marcin ‘Icewall’ Noga of Cisco Talos. |
| id | SSV:96526 |
| last seen | 2017-11-19 |
| modified | 2017-09-19 |
| published | 2017-09-19 |
| reporter | Root |
| title | Lexmark Perceptive Document Filters XLS ShapeHLink Information Disclosure Vulnerability(CVE-2017-2806) |
Talos
| id | TALOS-2017-0302 |
| last seen | 2019-05-29 |
| published | 2017-04-18 |
| reporter | Talos Intelligence |
| source | http://www.talosintelligence.com/vulnerability_reports/TALOS-2017-0302 |
| title | Lexmark Perceptive Document Filters XLS ShapeHLink Information Disclosure Vulnerability |