Headline
CVE-2020-27799: Heap buffer overflow in acc_ua_get_be32() · Issue #391 · upx/upx
A heap-based buffer over-read was discovered in the acc_ua_get_be32 function in miniacc.h in UPX 4.0.0 via a crafted Mach-O file.
==21053==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6160000014bb at pc 0x000000755961 bp 0x7ffe38d0c080 sp 0x7ffe38d0c078
READ of size 1 at 0x6160000014bb thread T0
#0 0x755960 in acc_ua_get_be32(void const*) /src/upx-multi/src/./miniacc.h:6099:12
#1 0x755960 in get_be32(void const*) /src/upx-multi/src/./bele.h:78:12
#2 0x755960 in N_BELE_RTP::BEPolicy::get32(void const*) const /src/upx-multi/src/./bele_policy.h:115:18
#3 0x58a254 in Packer::get_te32(void const*) const /src/upx-multi/src/./packer.h:296:65
#4 0x58a254 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:1601:32
#5 0x588959 in PackLinuxElf32::PackLinuxElf32help1(InputFile*) /src/upx-multi/src/p_lx_elf.cpp:305:13
#6 0x5d70d4 in PackLinuxElf32Be::PackLinuxElf32Be(InputFile*) /src/upx-multi/src/./p_lx_elf.h:385:9
#7 0x5d70d4 in PackLinuxElf32armBe::PackLinuxElf32armBe(InputFile*) /src/upx-multi/src/p_lx_elf.cpp:4969:58
#8 0x6e50c0 in PackMaster::visitAllPackers(Packer* (*)(Packer*, void*), InputFile*, options_t const*, void*) /src/upx-multi/src/packmast.cpp:196:9
#9 0x6e8ff1 in PackMaster::getUnpacker(InputFile*) /src/upx-multi/src/packmast.cpp:248:18
#10 0x6e8ff1 in PackMaster::unpack(OutputFile*) /src/upx-multi/src/packmast.cpp:266:9
#11 0x75826b in do_one_file(char const*, char*) /src/upx-multi/src/work.cpp:160:12
#12 0x7597c2 in do_files(int, int, char**) /src/upx-multi/src/work.cpp:271:13
#13 0x555aed in main /src/upx-multi/src/main.cpp:1538:5
#14 0x7fcbbeced83f in __libc_start_main /build/glibc-e6zv40/glibc-2.23/csu/../csu/libc-start.c:291
#15 0x41ce98 in _start (/out/upx-multi/upx-multi+0x41ce98)
0x6160000014bb is located 4 bytes to the right of 567-byte region [0x616000001280,0x6160000014b7)
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/./miniacc.h:6099:12 in acc_ua_get_be32(void const*)
Shadow bytes around the buggy address:
0x0c2c7fff8240: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c2c7fff8250: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c2c7fff8260: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c2c7fff8270: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c2c7fff8280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c2c7fff8290: 00 00 00 00 00 00 07[fa]fa fa fa fa fa fa fa fa
0x0c2c7fff82a0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c2c7fff82b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c2c7fff82c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c2c7fff82d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c2c7fff82e0: 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
==21053==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
Copyright (C) 1996-2020 Markus Franz Xaver Johannes Oberhumer
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