Heap overflow in csum_replace4() #488
Description
A heap-based buffer overflow was discovered in tcpreplay-edit binary, during the incremental checksum operation. The issue is being triggered in the function csum_replace4() at incremental_checksum.h, invoked by ipv4_l34_csum_replace() in edit_packet.c.
Tested version:
4.3
Command:
tcpreplay-edit --portmap=80:8000 --seed=10 --cachefile=example.cache --intf1=eno1 --intf2=eno3 --decode=some --preload-pcap --verbose $POC
Debugging:
95 static inline void csum_replace4(__sum16 *sum, __be32 from, __be32 to)
96 {
// sum=0xbfffe8f0 -> [...] -> 0xa8c0b0af
-> 97 *sum = csum_fold(csum_add(csum_sub(~csum_unfold(*sum), from), to)); //Buffer overflow
98 }
gef> p (unsigned short *)sum
$20 = (unsigned short *) 0xb6001742
gef> x 0xb6001742
0xb6001742: 391171182
ASAN Report
==7737==ERROR: AddressSanitizer: heap-buffer-overflow on address 0xb6001742 at pc 0x0806a35c bp 0xbff60578 sp 0xbff60568
READ of size 2 at 0xb6001742 thread T0
#0 0x806a35b in csum_replace4 /home/loginsoft/ACE/tcpreplay/src/tcpedit/incremental_checksum.h:97
#1 0x806acf1 in ipv4_l34_csum_replace /home/loginsoft/ACE/tcpreplay/src/tcpedit/edit_packet.c:181
#2 0x806afdb in ipv4_addr_csum_replace /home/loginsoft/ACE/tcpreplay/src/tcpedit/edit_packet.c:251
#3 0x806b633 in randomize_ipv4 /home/loginsoft/ACE/tcpreplay/src/tcpedit/edit_packet.c:343
#4 0x806661b in tcpedit_packet /home/loginsoft/ACE/tcpreplay/src/tcpedit/tcpedit.c:272
#5 0x805158a in send_packets /home/loginsoft/ACE/tcpreplay/src/send_packets.c:554
#6 0x8063193 in replay_file /home/loginsoft/ACE/tcpreplay/src/replay.c:188
#7 0x8061fb0 in tcpr_replay_index /home/loginsoft/ACE/tcpreplay/src/replay.c:61
#8 0x8060e80 in tcpreplay_replay /home/loginsoft/ACE/tcpreplay/src/tcpreplay_api.c:1135
#9 0x80586ea in main /home/loginsoft/ACE/tcpreplay/src/tcpreplay.c:139
#10 0xb7831636 in __libc_start_main (/lib/i386-linux-gnu/libc.so.6+0x18636)
#11 0x804a985 (/usr/local/bin/tcpreplay-edit+0x804a985)
0xb6001742 is located 4 bytes to the right of 62-byte region [0xb6001700,0xb600173e)
allocated by thread T0 here:
#0 0xb7accdee in malloc (/usr/lib/i386-linux-gnu/libasan.so.2+0x96dee)
#1 0x808c354 in _our_safe_malloc /home/loginsoft/ACE/tcpreplay/src/common/utils.c:50
#2 0x805515d in get_next_packet /home/loginsoft/ACE/tcpreplay/src/send_packets.c:1044
#3 0x80506d1 in preload_pcap_file /home/loginsoft/ACE/tcpreplay/src/send_packets.c:445
#4 0x8058626 in main /home/loginsoft/ACE/tcpreplay/src/tcpreplay.c:126
#5 0xb7831636 in __libc_start_main (/lib/i386-linux-gnu/libc.so.6+0x18636)
SUMMARY: AddressSanitizer: heap-buffer-overflow /home/loginsoft/ACE/tcpreplay/src/tcpedit/incremental_checksum.h:97 csum_replace4
Shadow bytes around the buggy address:
0x36c00290: 00 00 00 04 fa fa fa fa 00 00 00 00 00 00 00 04
0x36c002a0: fa fa fa fa 00 00 00 00 00 00 00 04 fa fa fa fa
0x36c002b0: 00 00 00 00 00 00 00 04 fa fa fa fa 00 00 00 00
0x36c002c0: 00 00 00 04 fa fa fa fa 00 00 00 00 00 00 00 04
0x36c002d0: fa fa fa fa 00 00 00 00 00 00 00 06 fa fa fa fa
=>0x36c002e0: 00 00 00 00 00 00 00 06[fa]fa fa fa 00 00 00 00
0x36c002f0: 00 00 04 fa fa fa fa fa 00 00 00 00 00 00 04 fa
0x36c00300: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x36c00310: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x36c00320: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x36c00330: 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
Heap right redzone: fb
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack partial redzone: f4
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
==7737==ABORTING
Please check if you are able to reproduce the issue via the Reproducer file