Headline
CVE-2020-27796: Heap buffer overflow in PackLinuxElf32::invert_pt_dynamic · Issue #392 · upx/upx
A heap-based buffer over-read was discovered in the invert_pt_dynamic function in p_lx_elf.cpp in UPX 4.0.0 via a crafted Mach-O file.
==21202==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x62f00000c530 at pc 0x00000058b076 bp 0x7ffdc9ecf670 sp 0x7ffdc9ecf668
READ of size 4 at 0x62f00000c530 thread T0
#0 0x58b075 in PackLinuxElf32::invert_pt_dynamic(N_Elf::Dyn<N_Elf::ElfITypes<LE16, LE32, LE32, LE32, LE32> > const*) /src/upx-multi/src/p_lx_elf.cpp:1676:25
#1 0x588959 in PackLinuxElf32::PackLinuxElf32help1(InputFile*) /src/upx-multi/src/p_lx_elf.cpp:305:13
#2 0x5d5e74 in PackLinuxElf32Le::PackLinuxElf32Le(InputFile*) /src/upx-multi/src/./p_lx_elf.h:395:9
#3 0x5d5e74 in PackLinuxElf32x86::PackLinuxElf32x86(InputFile*) /src/upx-multi/src/p_lx_elf.cpp:4838:54
#4 0x5d6261 in PackBSDElf32x86::PackBSDElf32x86(InputFile*) /src/upx-multi/src/p_lx_elf.cpp:4855:50
#5 0x5d6261 in PackFreeBSDElf32x86::PackFreeBSDElf32x86(InputFile*) /src/upx-multi/src/p_lx_elf.cpp:4866:58
#6 0x6e4460 in PackMaster::visitAllPackers(Packer* (*)(Packer*, void*), InputFile*, options_t const*, void*) /src/upx-multi/src/packmast.cpp:190:9
#7 0x6e8ff1 in PackMaster::getUnpacker(InputFile*) /src/upx-multi/src/packmast.cpp:248:18
#8 0x6e8ff1 in PackMaster::unpack(OutputFile*) /src/upx-multi/src/packmast.cpp:266:9
#9 0x75826b in do_one_file(char const*, char*) /src/upx-multi/src/work.cpp:160:12
#10 0x7597c2 in do_files(int, int, char**) /src/upx-multi/src/work.cpp:271:13
#11 0x555aed in main /src/upx-multi/src/main.cpp:1538:5
#12 0x7efe5d03d83f in __libc_start_main /build/glibc-e6zv40/glibc-2.23/csu/../csu/libc-start.c:291
#13 0x41ce98 in _start (/out/upx-multi/upx-multi+0x41ce98)
0x62f00000c532 is located 0 bytes to the right of 49458-byte region [0x62f000000400,0x62f00000c532)
allocated by thread T0 here:
#0 0x49519d in malloc (/out/upx-multi/upx-multi+0x49519d)
#1 0x569797 in MemBuffer::alloc(unsigned long long) /src/upx-multi/src/mem.cpp:194:42
SUMMARY: AddressSanitizer: heap-buffer-overflow /src/upx-multi/src/p_lx_elf.cpp:1676:25 in PackLinuxElf32::invert_pt_dynamic(N_Elf::Dyn<N_Elf::ElfITypes<LE16, LE32, LE32, LE32, LE32> > const*)
Shadow bytes around the buggy address:
0x0c5e7fff9850: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c5e7fff9860: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c5e7fff9870: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c5e7fff9880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c5e7fff9890: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c5e7fff98a0: 00 00 00 00 00 00[02]fa fa fa fa fa fa fa fa fa
0x0c5e7fff98b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c5e7fff98c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c5e7fff98d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c5e7fff98e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c5e7fff98f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
Shadow gap: cc
==21202==ABORTING
upx 4.0.0-git-87b73e5cfdc1+
UCL data compression library 1.03
zlib data compression library 1.2.8
LZMA SDK version 4.43
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Copyright (C) 1996-2020 Laszlo Molnar
Copyright (C) 2000-2020 John F. Reiser
Copyright (C) 2002-2020 Jens Medoch
Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler
Copyright (C) 1999-2006 Igor Pavlov
UPX comes with ABSOLUTELY NO WARRANTY; for details t