Sockets, Shellcode, Porting, and Coding: Reverse Engineering Exploits and Tool Coding for Security Professionals

96 If the source buffer is greater than the destination buffer, an overflow will occur.

Also, ensure that the destination buffer is null terminated to prevent future functions

that utilize the destination buffer from having any problems.

97

98

Example insecure implementation snippet:

99 char dest[20];

100 gets(dest);

101

102

Example secure implementation snippet:

103 char dest[20] = {0};

104 fgets(dest, sizeof(dest)-1, stdin);

105

106

Function name: fgets

107 Class: Buffer Overflow

108 Prototype: char *fgets(char *s, int size, FILE *stream);

109 Include: #include <stdio.h>

110 Description:

111 If the source buffer is greater than the destination buffer, an overflow will occur.

Also, ensure that the destination buffer is null terminated to prevent future functions ...