Bug Hunter Diary

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The OS X system froze immediately, and I got the followingdebugger output on the Linux host:Program received signal SIGTRAP, Trace/breakpoint trap.0x0035574c in ttsetcompat (tp=0x37e0804, com=0x8004741b, data=0x2522beb8 "",term=0x3) at /SourceCache/xnu/xnu-792.13.8/bsd/kern/tty_compat.c:145145 */→To see what exactly caused the SIGTRAP signal, I looked at the lastexecuted kernel instruction (see Section B.4 for a description of thefollowing debugger commands):(gdb) x/1i $eip0x35574c : call *0x456860(%eax)Apparently, the crash occurred when the kernel tried to call anaddress referenced by the EAX register. Next, I looked at the registervalues:(gdb) info registerseax 0xe0000000 -536870912ecx 0x4000001 67108865edx 0x386c380 59163520ebx 0xff000000 -16777216esp 0x2522bc18 0x2522bc18ebp 0x2522bd18 0x2522bd18esi 0x37e0804 58591236edi 0x0 0eip 0x35574c 0x35574ceflags 0x10287 66183cs 0x8 8ss 0x10 16ds 0x4b0010 4915216es 0x340010 3407888fs 0x25220010 622985232gs 0x48 72The debugger output shows that EAX had a value of 0xe0000000. Itwasn’t apparent to me where this value came from, so I disassembledthe instructions around EIP:(gdb) x/6i $eip - 150x35573d : mov %ebx,%eax0x35573f : shl $0x5,%eax0x355742 : mov %esi,0x4(%esp,1)0x355746 : mov 0xffffffa8(%ebp),%ecx0x355749 : mov %ecx,(%esp,1)0x35574c : call *0x456860(%eax)← Note that thedisassembly is inAT&T style.At address 0x35573d, the value of EBX is copied into EAX. The nextinstruction modifies this value by a left shift of 5 bits. At address124 Chapter 7
0x35574c, the value is used to calculate the operand of the callinstruction. So where did the value of EBX come from? A quick lookat the register values revealed that EBX was holding the value 0xff000000,the value I had supplied as input data for the TIOCSETD IOCTL. Thevalue 0xe0000000 was the result of a left shift of my supplied input valueby 5 bits. As expected, I was able to control the memory location usedto find the new value for the EIP register. The modification of my suppliedinput data can be expressed asaddress of the new value for EIP = (IOCTL input data value
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A Bug Hunter’s Diary. Copyright
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Chapter 3: Escape from the WWW Zone
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B.2 The Windows Debugger (WinDbg) .
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IntroductionWelcome to A Bug Hunter
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1Bug HuntingBug hunting is the proc
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After I’ve found a bug, I want to
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Table 1-1: Debuggers Used in This B
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2Back to the ’90sSunday, October
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16361637 /* clear the SEQ table */1
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If a TiVo file is loaded by VLC, th
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Get the →vulnerableWindows versio
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EIP = 41414141 . . . Mission EIP co
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NoteTo configure Process Explorer t
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See the following excerpt from the
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3. Immunity Debugger is a great Win
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NoteInput/output controls (IOCTLs)
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msgbb_datapdatabb_rptrdb_basedatabu
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8180 /*8181 * Null terminate the st
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26736 /*26737 * SIOC[GS]TUNPARAM ap
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19165 * are also rejected as they i
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01 #include 02 #include 03 #include
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fffffe8000f7e4b0 unix:die+da ()ffff
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zero pagenot mappedzero pageis mapp
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gaining full control over EIP/RIP a
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112 return 1;113 }114115 printf ("O
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solaris$ isainfo -b64I then compile
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ip_output+0x10()ip_wput+0x37()putne
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Notes1. The source code of OpenSola
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4.1 Vulnerability DiscoveryTo find
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167 if (current_track + 1 > fourxm-
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Step 1: Find a Sample 4X Movie File
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Next, I modified the values of trac
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Table 4-2: List of the Assembler In
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63 #elif defined (HAVE_MEMALIGN)64
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linux$ gdb -q ./ffmpeg_g(gdb) run -
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(UINT_MAX / sizeof(AudioTrack) - 1)
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7ebe000-b7ec0000 r--p 0015c000 08:0
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5Browse and You’re OwnedSunday, A
Page 87 and 88: {SWI.ClassId_q.ClassId clsid = new
Page 89 and 90: 27 except KeyboardInterrupt:28 prin
Page 91 and 92: Figure 5-4: Defining a breakpoint a
Page 93 and 94: Figure 5-7: User-controlled argumen
Page 95 and 96: Next, I tried to retrieve the size
Page 97 and 98: 05 06 arg = String(232, "A") + Stri
Page 99: iDefense VCPnotifiedVulnerability d
Page 102 and 103: 6.1 Vulnerability DiscoveryI used t
Page 104 and 105: Step 3: Check the Device Security S
Page 106 and 107: Below, the elements of the MajorFun
Page 108 and 109: At address .text:00010748, a pointe
Page 110 and 111: [..][..]//// Current stack location
Page 112 and 113: The transfer type is specified usin
Page 114 and 115: If the requested IOCTL code matches
Page 116 and 117: Figure 6-5: Graph view of the vulne
Page 118 and 119: .text:00010DBA push 1 ; _DWORD.text
Page 120 and 121: 99 // .text:00010DEF cmp dword ptr
Page 122 and 123: nt!RtlpBreakWithStatusInstruction:8
Page 124 and 125: After I gained control over EIP, I
Page 127 and 128: 7A Bug Older Than 4.4BSDSaturday, M
Page 129 and 130: Here are some examples:Source code
Page 131 and 132: 1094 return (ENXIO);1095 if (t != t
Page 133 and 134: 4. The assumed address of l_open()
Page 135 and 136: osx$ cat /Library/Logs/panic.logSat
Page 137: Back on the Linux host, I started t
Page 141 and 142: 48 define search_memloc49 set $max_
Page 143 and 144: As the debugger output shows, the E
Page 145: ApplenotifiedApple asks formore det
Page 148 and 149: I performed the following steps whe
Page 150 and 151: I then began fuzzing files of the A
Page 152 and 153: Figure 8-1: Playing the unmodifiedA
Page 154 and 155: • Line 40 copies the current proc
Page 156 and 157: As the debugger output shows, media
Page 158 and 159: The manipulated byte (0xff) that ca
Page 160 and 161: (gdb) x/12x 0x1301bfc0x1301bfc: 0x0
Page 162 and 163: ApplenotifiedApple confirmsthe vuln
Page 164 and 165: Every function of a process that is
Page 166 and 167: eip 0x43434343 0x43434343eflags 0x1
Page 168 and 169: The access violation is caused when
Page 170 and 171: is less than 12. If it is, the stri
Page 172 and 173: The program in Listing A-4 calls th
Page 174 and 175: 0x080483f3 : mov DWORD PTR [esp+0x4
Page 177 and 178: BDebuggingThis appendix contains in
Page 179 and 180: Information CommandsCommandDescript
Page 181 and 182: Information CommandsCommandrkbu add
Page 183 and 184: Figure B-3: Configuration settings
Page 185 and 186: Figure B-6: Attaching the kernel de
Page 187 and 188: Other CommandsCommandset disassembl
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linux# pwd/home/tk/gdb-292/srclinux
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Notes1. See the Solaris Modular Deb
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The many mitigation techniques coul
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Figure C-1: DEP and ASLR status sho
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08 p[0] = 0x41414141;09 printf (“
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ConclusionIn case of a buffer overf
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zonecfg:wwwzone> set autoboot=truez
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Notes1. See Rob King, “New Leopar
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COMRaider, 72coordinated disclosure
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Rreadelf, 161RELRO, 67-69, 183-186r
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A Bug Hunter’s Diary is set in Ne
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