alpine 3.9
buffer weakness #41

5

Weakness Breakdown


Definition:

Buffer overflows are one of the most well-known software vulnerabilities. Even though most developers know what buffer overflows are, attacks against the vulnerabilities are common in both legacy and newer applications. A classic buffer overflow exploit begins with the attacker sending data to a program, which it then stores in an undersized stack buffer. Besides stack buffer overflows, other kinds of buffer overflows include heap overflows, off-by-one errors and many others. Learn more about buffer overflows on OWASP attack index.

Warning code(s):

Does not check for buffer overflows.

File Name:

libraw/src/LibRaw-0.19.2/src/libraw_datastream.cpp

Context:

The highlighted line of code below is the trigger point of this particular Alpine 3.9 buffer weakness.

     break;
  case SEEK_CUR:
    dir = std::ios_base::cur;
    break;
  case SEEK_END:
    dir = std::ios_base::end;
    break;
  default:
    dir = std::ios_base::beg;
  }
  return f->pubseekoff((long)o, dir) < 0;
}

INT64 LibRaw_file_datastream::tell()
{
  if (substream)
    return substream->tell();
  LR_STREAM_CHK();
  return f->pubseekoff(0, std::ios_base::cur);
}

char *LibRaw_file_datastream::gets(char *str, int sz)
{
  if (substream)
    return substream->gets(str, sz);
  LR_STREAM_CHK();
  std::istream is(f.get());
  is.getline(str, sz);
  if (is.fail())
    return 0;
  return str;
}

int LibRaw_file_datastream::scanf_one(const char *fmt, void *val)
{
  if (substream)
    return substream->scanf_one(fmt, val);
  LR_STREAM_CHK();

  std::istream is(f.get());

  /* HUGE ASSUMPTION: *fmt is either "%d" or "%f" */
  if (strcmp(fmt, "%d") == 0)
  {
    int d;
    is >> d;
    if (is.fail())
      return EOF;
    *(static_cast<int *>(val)) = d;
  } 

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