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Invalid memory address dereference in getName (in util/decompile.c:408) #114

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fantasy7082 opened this issue Mar 7, 2018 · 1 comment · Fixed by #125
Closed

Invalid memory address dereference in getName (in util/decompile.c:408) #114

fantasy7082 opened this issue Mar 7, 2018 · 1 comment · Fixed by #125

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@fantasy7082
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Hi, i found a issue in the libming 0.4.8. It crashed in function getName.the details are below(ASAN):

./swftocxx 006-unknown-swf /dev/null 
header indicates a filesize of 522 but filesize is 538
#include <mingpp.h>


main(){
SWFMovie* m = new SWFMovie(48);

Ming_setScale(1.0);
m->setRate(48.187500);
m->setDimension(3992, 3680);

// SWF_SETBACKGROUNDCOLOR 
m->setBackground(0x30, 0x30, 0x30);

// SWF_DEFINESPRITE 

	//  MovieClip 12336 
SWFMovieClip* character12336 = new SWFMovieClip(); // 12336 frames 

// SWF_END 

// SWF_EXPORTASSETS 
m->addExport(character12336,"0000000000000000000");
m->writeExports();

// SWF_INITACTION 
// Might be more appropriate to use addInitAction here
m->add(new SWFInitAction(ASAN:SIGSEGV
=================================================================
==23943==ERROR: AddressSanitizer: SEGV on unknown address 0x60b0000287a8 (pc 0x000000411568 bp 0x7ffe0bbedf70 sp 0x7ffe0bbedf50 T0)
    #0 0x411567 in getName /root/libming-asan/util/decompile.c:408
    #1 0x41d38b in decompileCALLMETHOD /root/libming-asan/util/decompile.c:2865
    #2 0x41e7ea in decompileAction /root/libming-asan/util/decompile.c:3285
    #3 0x41eba0 in decompileActions /root/libming-asan/util/decompile.c:3419
    #4 0x41c727 in decompileDEFINEFUNCTION /root/libming-asan/util/decompile.c:2759
    #5 0x41e7b8 in decompileAction /root/libming-asan/util/decompile.c:3279
    #6 0x41eba0 in decompileActions /root/libming-asan/util/decompile.c:3419
    #7 0x41b07e in decompileIF /root/libming-asan/util/decompile.c:2581
    #8 0x41e715 in decompileAction /root/libming-asan/util/decompile.c:3260
    #9 0x41eba0 in decompileActions /root/libming-asan/util/decompile.c:3419
    #10 0x41eccd in decompile5Action /root/libming-asan/util/decompile.c:3441
    #11 0x40d221 in outputSWF_INITACTION /root/libming-asan/util/outputscript.c:1860
    #12 0x40e331 in outputBlock /root/libming-asan/util/outputscript.c:2083
    #13 0x40f3d9 in readMovie /root/libming-asan/util/main.c:286
    #14 0x40fb0e in main /root/libming-asan/util/main.c:359
    #15 0x7f21a68a882f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
    #16 0x401b58 in _start (/usr/local/libming-asan/bin/swftocxx+0x401b58)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /root/libming-asan/util/decompile.c:408 getName
==23943==ABORTING

POC FILE:https://github.com/fantasy7082/image_test/blob/master/006-unknown-swf

@hlef
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hlef commented Mar 12, 2018

Reproduced on latest master. Also a duplicate of issues #112, #123, #122, #120 and #117. I'll PR a patch soon.

FTR, this issue was assigned number CVE-2018-7872.

hlef added a commit to hlef/libming that referenced this issue Mar 12, 2018
Constants are usually retrieved from the constant pool without verifying
that the pool actually contains them, which may lead to various heap
buffer overflow issues.

In this patch we add a counter keeping track of how many elements the pool
contains, and checks making sure that whenever the pool is accessed, the
constant in present in the pool (constant position < pool counter).

Also, do not return "" when a pointer is excepted (it should be legal to free
this return value).

This patch fixes libming#112 (CVE-2018-7875), fixes libming#120 (CVE-2018-7871),
fixes libming#117 (CVE-2018-7870), fixes libming#114 (CVE-2018-7872), fixes libming#122,
fixes libming#123.
hlef added a commit to hlef/libming that referenced this issue Mar 12, 2018
Constants are usually retrieved from the constant pool without verifying
that the pool actually contains them, which may lead to various heap
buffer overflow issues.

In this patch we add a counter keeping track of how many elements the pool
contains, and checks making sure that whenever the pool is accessed, the
constant in present in the pool (constant position < pool counter).

Also, do not return "" when a pointer is excepted (it should be legal to free
this return value).

This patch fixes libming#112 (CVE-2018-7875), fixes libming#120 (CVE-2018-7871),
fixes libming#117 (CVE-2018-7870), fixes libming#114 (CVE-2018-7872), fixes libming#122,
fixes libming#113 (CVE-2018-7868), fixes libming#123.
@strk strk closed this as completed in #125 Mar 13, 2018
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2 participants