C++ buffer overflow
Date: 2023-02-16Last modified: 2023-06-27

Table of contents
char var1[4]; // stack
char var2[4]; // stack
char var3[4]; // stack
std::stringstream input( "1234567890\nABCDEFG\nRSTUVX" );
fmt::print( "var1 address: {}\n", static_cast<void *>( var1 ) );
fmt::print( "var2 address: {}\n", static_cast<void *>( var2 ) );
fmt::print( "var3 address: {}\n", static_cast<void *>( var3 ) );
fmt::print( "var1: '{}' var2: '{}' var3: '{}'\n", var1, var2, var3 );
fmt::print("Input -> var2\n");
input.getline( var2, '\n' );
fmt::print( "var1: '{}' var2: '{}' var3: '{}'\n", var1, var2, var3 );
fmt::print("Input -> var1\n");
input.getline( var1, '\n' );
fmt::print( "var1: '{}' var2: '{}' var3: '{}'\n", var1, var2, var3 );
Possible output
var1 address: 0x7fff65ac56ec
var2 address: 0x7fff65ac56e8
var3 address: 0x7fff65ac56e4
var1: '>��(_�e�' var2: 'k�U2>��(_�e�' var3: '����k�U2>��(_�e�'
Input -> var2
var1: '56789' var2: '123456789' var3: '����123456789'
Input -> var1
var1: '' var2: '1234' var3: '����1234'