用GCC编译上面的程序,同时注意关闭Buffer Overflow Protect开关: gcc -g -fno-stack-protector test.c -o test 为了找出返回地址,我用gdb调试上面编译出来的程序。 //(前面启动gdb,设置参数和断点的步骤省略……) (gdb)r Startingprogram:/media/Personal/MyProject/C/Stac
从上面的例子中不难看出,我们可以通过Buffer Overflow来改变在堆栈中存放的过程返回地址,从而改变整个程序的流程,使它转向任何我们想要它去的地方.这就为黑客们提供了可乘之机, 最常见的方法是: 在长字符串中嵌入一段代码,并将过程的返回地址覆盖为这段代码的地址, 这样当过程返回时,程序就转而开始执行这段我们自...
指的是一种系统攻击的手段，通过往程序的缓冲区写超出其长度的内容，造成缓冲区的溢出，从而破坏程序的堆栈，使程序转而执行其它指令，以达到攻击的目的。据统计，通过缓冲区溢出进行的攻击占所有系统攻击总数的80%以上。 造成缓冲区溢出的原因是程序中没有仔细检查用户输入的参数。例如下面程序: example1.c --- vo...
从上面的例子中不难看出,我们可以通过Buffer Overflow来改变在堆栈中存放的过程返回地址,从而改变整个程序的流程,使它转向任何我们想要它去的地方.这就为黑客们提供了可乘之机, 最常见的方法是: 在长字符串中嵌入一段代码,并将过程的返回地址覆盖为这段代码的地址, 这样当过程返回时,程序就转而开始执行这段我们自...
For example, a simple buffer overflow can be caused when code that relies on external data receives a ‘gets()’ function to read data in a stack buffer. The system cannot limit the data that is read by the function, which makes code safety reliant on users entering fewer than ‘BUFSIZE...
A buffer overflow occurs when data written to a buffer exceeds the length of the buffer, so that corrupting data values in memory addresses adjacent the end of the buffer. This often occurs when copying data into a buffer without sufficient bounds checking. ...
用GCC编译上面的程序,同时注意关闭Buffer Overflow Protect开关: gcc -g -fno-stack-protector test.c -o test 为了找出返回地址,我用gdb调试上面编译出来的程序。 //(前面启动gdb,设置参数和断点的步骤省略……) (gdb)r Startingprogram:/media/Personal/MyProject/C/StackOver/testabc ...
Unicode overflow- A unicode overflow creates a buffer overflow by inserting unicode characters into an input that expect ASCII characters. (ASCII and unicode are encoding standards that let computers represent text. For example the letter ‘a’ is represented by the number 97 in ASCII. While ASCII...
用GCC编译上面的程序,同时注意关闭Buffer Overflow Protect开关: gcc -g -fno-stack-protector test.c -o test 为了找出返回地址,我用gdb调试上面编译出来的程序。 //(前面启动gdb,设置参数和断点的步骤省略……) (gdb) r Starting program: /media/Personal/MyProject/C/StackOver/test abc Address of foo =...
bounds functionality checking to protect the buffer. Avoid using functions that do not check the buffer (for example, in the C language, replace gets() with fgets()). Use built-in protected languages or use special security programs in the language code to prevent buffer overflow vulnerabilities...