CVE-2017-11553: illegal address access in the extend_alias_table function in localealias.c

[rhertzog]

I'm forwarding a security vulnerability reported here:
https://bugzilla.redhat.com/show_bug.cgi?id=1471772

The file used to reproduce the issue is here:
https://bugzilla.redhat.com/attachment.cgi?id=1299839
(this is rar archive containing the actual reproducer file)

Here's a copy of the report:

$./exiv2 POC7

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff60f9135 in malloc_consolidate (av=av@entry=0x7ffff643ec00 <main_arena>) at malloc.c:4150
4150	malloc.c: No such file or directory.
(gdb) bt
#0  0x00007ffff60f9135 in malloc_consolidate (av=av@entry=0x7ffff643ec00 <main_arena>) at malloc.c:4150
#1  0x00007ffff60fba34 in _int_malloc (av=av@entry=0x7ffff643ec00 <main_arena>, bytes=bytes@entry=1600) at malloc.c:3417
#2  0x00007ffff60fe50e in __GI___libc_malloc (bytes=1600) at malloc.c:2895
#3  0x00007ffff60fffb8 in __libc_realloc (bytes=1600, oldmem=0x0) at malloc.c:2976
#4  realloc_hook_ini (ptr=0x0, sz=1600, caller=<optimized out>) at hooks.c:41
#5  0x00007ffff60fec17 in __GI___libc_realloc (oldmem=0x0, bytes=1600) at malloc.c:2965
#6  0x00007ffff60ac1cb in extend_alias_table () at localealias.c:397
#7  read_alias_file (fname=<optimized out>, fname_len=<optimized out>) at localealias.c:319
#8  0x00007ffff60ac3c7 in _nl_expand_alias (name=name@entry=0x7fffffffae30 "en_US.UTF-8") at localealias.c:203
#9  0x00007ffff60aa608 in _nl_find_domain (dirname=dirname@entry=0x7ffff620ea00 <_nl_default_dirname> "/usr/share/locale", locale=locale@entry=0x7fffffffae30 "en_US.UTF-8", 
    domainname=domainname@entry=0x7fffffffae50 "LC_MESSAGES/libc.mo", domainbinding=domainbinding@entry=0x0) at finddomain.c:124
#10 0x00007ffff60a9e72 in __dcigettext (domainname=0x7ffff6206229 <_libc_intl_domainname> "libc", msgid1=0x7ffff6206711 "Cannot allocate memory", msgid2=msgid2@entry=0x0, plural=plural@entry=0, 
    n=n@entry=0, category=category@entry=5) at dcigettext.c:722
#11 0x00007ffff60a8a8f in __GI___dcgettext (domainname=<optimized out>, msgid=<optimized out>, category=category@entry=5) at dcgettext.c:47
#12 0x00007ffff610558e in __GI___strerror_r (errnum=12, buf=0x7fffffffb0b0 "", buflen=1024) at _strerror.c:71
#13 0x00000000005706ef in Exiv2::strError() ()
#14 0x00000000004c11b8 in Exiv2::FileIo::mmap(bool) ()
#15 0x00000000006b8f3f in Exiv2::TiffImage::readMetadata() ()
#16 0x0000000000464434 in Action::Print::printSummary() ()
#17 0x0000000000463e5c in Action::Print::run(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) ()
#18 0x0000000000439762 in main ()

icy@ubuntu:~/real/exiv2-asan/install/bin$ ./exiv2 ../../../exiv2_coll4/coll-out1/crashes/id\:000015\,sig\:11\,src\:001021\,op\:flip32\,pos\:47 
ASAN:SIGSEGV
=================================================================
==47987==ERROR: AddressSanitizer: SEGV on unknown address 0x00a09ffca08b (pc 0x7efe16b0fec5 bp 0x7ffca809dd00 sp 0x7ffca809d600 T0)
    #0 0x7efe16b0fec4  (/home/icy/real/exiv2-asan/install/lib/libexiv2.so.26+0x434ec4)
    #1 0x7efe16b180e0  (/home/icy/real/exiv2-asan/install/lib/libexiv2.so.26+0x43d0e0)
    #2 0x7efe16d28900  (/home/icy/real/exiv2-asan/install/lib/libexiv2.so.26+0x64d900)
    #3 0x7efe16d205eb  (/home/icy/real/exiv2-asan/install/lib/libexiv2.so.26+0x6455eb)
    #4 0x518d8b  (/home/icy/real/exiv2-asan/install/bin/exiv2+0x518d8b)
    #5 0x518488  (/home/icy/real/exiv2-asan/install/bin/exiv2+0x518488)
    #6 0x4e2ebb  (/home/icy/real/exiv2-asan/install/bin/exiv2+0x4e2ebb)
    #7 0x7efe15888abf  (/lib/x86_64-linux-gnu/libc.so.6+0x20abf)
    #8 0x43b288  (/home/icy/real/exiv2-asan/install/bin/exiv2+0x43b288)

AddressSanitizer can not provide additional info.
==47987==ABORTING

This vulnerability is detected by team OWL337, with our custom fuzzer collAFL. Please contact ganshuitao@gmail.com and chaoz@tsinghua.edu.cn if you need more info about the team, the tool or the vulnerability.

[fgeek]

I can confirm the crash with Git 31fc5d2

[D4N]

This has been fixed on master. I'll add the reproducer and check if it has been fixed on 0.26 too.

[carnil]

Hi

On Wed, Oct 18, 2017 at 11:13:22PM +0000, D4N wrote: This has been fixed on master. I'll add the reproducer and check if it has been fixed on 0.26 too.

Which commit in master fixes the issue?

[D4N]

I'll have to find out. This issue slipped through when I was fixing them. However, it won't be a single commit that fixes this issue.

I guess you are the package maintainer of exiv2 for Debian? In that case, you'll get all the security fixes for all the CVEs from the 0.26 branch. We have backported only security fixes and the respective tests (although this will be only fully completed after #127 is merged).

[D4N]

@carnil This was fixed ultimately by 74cb5ba, but you'll definitely need 6e3855a and 8a8f60a for that too. If you want to include the fixes for big-tiff processing you should find the commits in #105.