[Bug]heap buffer overflow in tcpprep with get_l2len()

[jimoyong]

Describe the bug
A heap buffer overflow found in tcpprep with get_l2len().

ASAN report:

==83==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000000034 at pc 0x0000004e1900 bp 0x7fffed14c660 sp 0x7fffed14c658
READ of size 2 at 0x602000000034 thread T0
    #0 0x4e18ff in get_l2len /src/tcpreplay-4.3.3/src/common/get.c:191:22
    #1 0x4e1b2b in get_ipv4 /src/tcpreplay-4.3.3/src/common/get.c:267:14
    #2 0x4c8c99 in process_raw_packets /src/tcpreplay-4.3.3/src/tcpprep.c:370:41
    #3 0x4c8c99 in main /src/tcpreplay-4.3.3/src/tcpprep.c:147:23
    #4 0x7f3c98e6683f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f)
    #5 0x41c348 in _start (/out/tcpreplay+0x41c348)    _### //I just rename tcpprep to tcpreplay//_

0x602000000034 is located 0 bytes to the right of 4-byte region [0x602000000030,0x602000000034)
allocated by thread T0 here:
    #0 0x49619d in malloc (/out/tcpreplay+0x49619d)
    #1 0x7f3c99f904fe  (/usr/lib/x86_64-linux-gnu/libpcap.so.0.8+0x1f4fe)

SUMMARY: AddressSanitizer: heap-buffer-overflow /src/tcpreplay-4.3.3/src/common/get.c:191:22 in get_l2len
Shadow bytes around the buggy address:
  0x0c047fff7fb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c047fff7ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c047fff8000: fa fa 00 03 fa fa[04]fa fa fa fa fa fa fa fa fa
  0x0c047fff8010: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8020: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8030: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8040: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fff8050: 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
==83==ABORTING

To Reproduce
Steps to reproduce the behavior:

1. download tcpreplay-4.3.3.tar.gz
2. apt-get -y install libpcap-dev
3. cd tcpreplay-3.4.4 && ./congfigure && make && make install
4. tcpprep -a client -i [poc_filename] -o a.cach

poc_tcpprep_heap_buffer_overflow_get_l2len.tar.gz

Expected behavior
Get an a.cach at the path or exit when meet abnormal input.

System (please complete the following information):

• Tcpreplay Version 4.3.3 tcpprep -V

tcpprep version: 4.3.3 (build git:v4.3.3)
Copyright 2013-2018 by Fred Klassen <tcpreplay at appneta dot com> - AppNeta
Copyright 2000-2012 by Aaron Turner <aturner at synfin dot net>
The entire Tcpreplay Suite is licensed under the GPLv3
Cache file supported: 04
Not compiled with libdnet.
Compiled against libpcap: 1.7.4
64 bit packet counters: enabled
Verbose printing via tcpdump: disabled

OS: ubuntu-16.04.6 x86_64

Additional context
None.

[carnil]

CVE-2020-24266 got assigned for this issue.

[fklassen]

Fixed in #616 and PR #637. PR #638 updates changelog.

[fklassen]

From mail lists:

Hi,

The following vulnerability was published for tcpreplay.

CVE-2020-24266[0]:
| An issue was discovered in tcpreplay tcpprep v4.3.3. There is a heap
| buffer overflow vulnerability in get_l2len() that can make tcpprep
| crash and cause a denial of service.

If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2020-24266
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-24266
[1] #617

Please adjust the affected versions in the BTS as needed.

Regards,
Salvatore