Description

Heap-based Buffer Overflow in function get_lisp_indent at indent.c:1994

vim version

git log
commit 83497f875881973df772cc4cc593766345df6c4a (HEAD -> master, tag: v8.2.5105, origin/master, origin/HEAD)

POC

./vim -u NONE -i NONE -n -m -X -Z -e -s -S /mnt/share/max/fuzz/poc/vim/poc_hbo2_s.dat -c :qa!

=================================================================
==2361==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x621000013d00 at pc 0x0000009a0535 bp 0x7ffcbe3e9ab0 sp 0x7ffcbe3e9aa8
READ of size 1 at 0x621000013d00 thread T0
    #0 0x9a0534 in get_lisp_indent /home/fuzz/fuzz/vim/afl/src/indent.c:1994:36
    #1 0x99f221 in op_reindent /home/fuzz/fuzz/vim/afl/src/indent.c:1101:16
    #2 0xbb091d in do_pending_operator /home/fuzz/fuzz/vim/afl/src/ops.c:4057:7
    #3 0xb1fa03 in normal_cmd /home/fuzz/fuzz/vim/afl/src/normal.c:961:2
    #4 0x814eee in exec_normal /home/fuzz/fuzz/vim/afl/src/ex_docmd.c:8808:6
    #5 0x814718 in exec_normal_cmd /home/fuzz/fuzz/vim/afl/src/ex_docmd.c:8771:5
    #6 0x8142c9 in ex_normal /home/fuzz/fuzz/vim/afl/src/ex_docmd.c:8689:6
    #7 0x7dd249 in do_one_cmd /home/fuzz/fuzz/vim/afl/src/ex_docmd.c:2570:2
    #8 0x7ca105 in do_cmdline /home/fuzz/fuzz/vim/afl/src/ex_docmd.c:992:17
    #9 0xe58b5e in do_source_ext /home/fuzz/fuzz/vim/afl/src/scriptfile.c:1674:5
    #10 0xe555f6 in do_source /home/fuzz/fuzz/vim/afl/src/scriptfile.c:1801:12
    #11 0xe54f33 in cmd_source /home/fuzz/fuzz/vim/afl/src/scriptfile.c:1174:14
    #12 0xe5463e in ex_source /home/fuzz/fuzz/vim/afl/src/scriptfile.c:1200:2
    #13 0x7dd249 in do_one_cmd /home/fuzz/fuzz/vim/afl/src/ex_docmd.c:2570:2
    #14 0x7ca105 in do_cmdline /home/fuzz/fuzz/vim/afl/src/ex_docmd.c:992:17
    #15 0x7ced81 in do_cmdline_cmd /home/fuzz/fuzz/vim/afl/src/ex_docmd.c:586:12
    #16 0x1422702 in exe_commands /home/fuzz/fuzz/vim/afl/src/main.c:3133:2
    #17 0x141e89b in vim_main2 /home/fuzz/fuzz/vim/afl/src/main.c:780:2
    #18 0x1413dad in main /home/fuzz/fuzz/vim/afl/src/main.c:432:12
    #19 0x7fe23555b082 in __libc_start_main /build/glibc-SzIz7B/glibc-2.31/csu/../csu/libc-start.c:308:16
    #20 0x41ea4d in _start (/home/fuzz/fuzz/vim/afl/src/vim+0x41ea4d)

0x621000013d00 is located 0 bytes to the right of 4096-byte region [0x621000012d00,0x621000013d00)
allocated by thread T0 here:
    #0 0x499cad in malloc (/home/fuzz/fuzz/vim/afl/src/vim+0x499cad)
    #1 0x4cb382 in lalloc /home/fuzz/fuzz/vim/afl/src/alloc.c:246:11
    #2 0x4cb26a in alloc /home/fuzz/fuzz/vim/afl/src/alloc.c:151:12
    #3 0x142bfb5 in mf_alloc_bhdr /home/fuzz/fuzz/vim/afl/src/memfile.c:884:21
    #4 0x142adc7 in mf_new /home/fuzz/fuzz/vim/afl/src/memfile.c:375:26
    #5 0xa60d28 in ml_new_data /home/fuzz/fuzz/vim/afl/src/memline.c:4080:15
    #6 0xa5f6d1 in ml_open /home/fuzz/fuzz/vim/afl/src/memline.c:394:15
    #7 0x501c8a in open_buffer /home/fuzz/fuzz/vim/afl/src/buffer.c:186:9
    #8 0x141ff4c in create_windows /home/fuzz/fuzz/vim/afl/src/main.c:2902:9
    #9 0x141e21a in vim_main2 /home/fuzz/fuzz/vim/afl/src/main.c:711:5
    #10 0x1413dad in main /home/fuzz/fuzz/vim/afl/src/main.c:432:12
    #11 0x7fe23555b082 in __libc_start_main /build/glibc-SzIz7B/glibc-2.31/csu/../csu/libc-start.c:308:16

SUMMARY: AddressSanitizer: heap-buffer-overflow /home/fuzz/fuzz/vim/afl/src/indent.c:1994:36 in get_lisp_indent
Shadow bytes around the buggy address:
  0x0c427fffa750: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c427fffa760: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c427fffa770: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c427fffa780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x0c427fffa790: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x0c427fffa7a0:[fa]fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c427fffa7b0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c427fffa7c0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c427fffa7d0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c427fffa7e0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c427fffa7f0: 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
==2361==ABORTING

poc_hbo2_s.dat

Impact

This vulnerabilities are capable of crashing software, modify Memory, and possible remote execution