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The behavior of this non-compliant example is undefined becuase because the size() of bs is 8 but the index used to reference bs ranges from 0 through 99.

string bs("01234567");
for (int i=0; i<100; i++) {
  bs[i] = '\0'';
}

This program does not typically raise an exception and is likely to crash.

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The following compliant solution uses the {{basic_string at()}} method which behaves in a similar fashion to the index {{operator\[\]}} but throws an {{out_of_range}} exception if {{pos >= size()}}.

string bs("01234567");
try {
  for (int i=0; i<100; i++) {
    bs.at(i) = '\0';
  }
}
catch (...) {
  cerr << "Index out of range" << endl;
}

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Unchecked element access can lead to out-of-bounds read reads and writes and write-anywhere exploits. These exploits can in turn lead to the execution of arbitrary code with the permissions of the vulnerable process.

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