Headline

CVE-2020-21680: Xfig / Tickets / #74 stack-buffer-overflow in put_arrow at genpict2e.c:1191

A stack-based buffer overflow in the put_arrow() component in genpict2e.c of fig2dev 3.2.7b allows attackers to cause a denial of service (DOS) via converting a xfig file into pict2e format.

3 years ago

CVE

Open in Source

#dos #git #c++#buffer_overflow

Summary
Files
Reviews
Support
Tickets
Discussion
Git ▾
- fig2dev
- xfig

Menu ▾ ▴

Status: closed

Owner: nobody

Labels: None

Updated: 2020-12-21

Created: 2019-12-28

Private: No

Hi,
I found a stack-buffer-overflow in put_arrow at genpict2e.c:1191
Please run following command to reproduce it,

ASAN LOG

==39178==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fffc3316ec8 at pc 0x00000077150d bp 0x7fffc3316e70 sp 0x7fffc3316e68 READ of size 4 at 0x7fffc3316ec8 thread T0 #0 0x77150c in put_arrow /home/tmp/mcj-fig2dev/fig2dev/dev/genpict2e.c:1191:39 #1 0x767f69 in genpict2e_arc /home/tmp/mcj-fig2dev/fig2dev/dev/genpict2e.c:2575:6 #2 0x54b8bb in gendev_objects /home/tmp/mcj-fig2dev/fig2dev/fig2dev.c:1003:6 #3 0x54b8bb in main /home/tmp/mcj-fig2dev/fig2dev/fig2dev.c:480 #4 0x7f8b1eb44b96 in __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/…/csu/libc-start.c:310 #5 0x41b3a9 in _start (/home/tmp/fig2dev+0x41b3a9)

Address 0x7fffc3316ec8 is located in stack of thread T0 at offset 72 in frame #0 0x76d4cf in put_arrow /home/tmp/mcj-fig2dev/fig2dev/dev/genpict2e.c:1152

This frame has 9 object(s): [32, 36) ‘sx’ (line 1153) [48, 52) ‘sy’ (line 1153) [64, 68) ‘lx’ (line 1153) <== Memory access at offset 72 overflows this variable [80, 480) ‘points’ (line 1154) <== Memory access at offset 72 underflows this variable [544, 944) ‘fillpoints’ (line 1154) [1008, 1408) ‘clippts’ (line 1154) [1472, 1476) ‘npoints’ (line 1155) [1488, 1492) ‘nfillpoints’ (line 1155) [1504, 1508) ‘nclippts’ (line 1155) HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext (longjmp and C++ exceptions *are* supported) SUMMARY: AddressSanitizer: stack-buffer-overflow /home/tmp/mcj-fig2dev/fig2dev/dev/genpict2e.c:1191:39 in put_arrow Shadow bytes around the buggy address: 0x10007865ad80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10007865ad90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10007865ada0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10007865adb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10007865adc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>0x10007865add0: f1 f1 f1 f1 04 f2 04 f2 04[f2]00 00 00 00 00 00 0x10007865ade0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10007865adf0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10007865ae00: 00 00 00 00 00 00 00 00 00 00 00 00 f2 f2 f2 f2 0x10007865ae10: f2 f2 f2 f2 00 00 00 00 00 00 00 00 00 00 00 00 0x10007865ae20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 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 ==39178==ABORTING

fig2dev Version 3.2.7b
I also tested this in git Commit [3065ab] and can reproduce it.

1 Attachments

Related

Commit: [3065ab]

Discussion