From b6f097c03520502aea6c9c8153a0b95226b431a0 Mon Sep 17 00:00:00 2001 From: Brent Cook Date: Tue, 15 Nov 2016 08:08:20 -0600 Subject: [PATCH] Correct a few misspellings --- .../modules/exploit/linux/samba/lsa_transnames_heap.md | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/documentation/modules/exploit/linux/samba/lsa_transnames_heap.md b/documentation/modules/exploit/linux/samba/lsa_transnames_heap.md index 09ba3d7f25..477e7f57c2 100644 --- a/documentation/modules/exploit/linux/samba/lsa_transnames_heap.md +++ b/documentation/modules/exploit/linux/samba/lsa_transnames_heap.md @@ -1,6 +1,6 @@ ## Vulnerable Application - Samba 3.0.0 through 3.0.25rc3 are vulnerable to mulitple heap overflows. This module targets a heap overflow in the LsarLookupSids RPC call (CVE-2007-2446), causing an overflow in the function lsa\_io\_trans_name(). + Samba 3.0.0 through 3.0.25rc3 are vulnerable to multiple heap overflows. This module targets a heap overflow in the LsarLookupSids RPC call (CVE-2007-2446), causing an overflow in the function lsa\_io\_trans_name(). The exploit uses the heap overflow to overwrite a function pointer contained in the metadata of the TALLOC memory allocator, a technique which only works on Samba versions 3.0.21-3.0.24. @@ -19,15 +19,15 @@ ### MIPS nop generator - The exploit uses a heap overflow to put a large nop sled in memory to decrease the accuracy needed in the initial redirection of code flow. A nop sled is a large section of contiguous instructions which do nothing. When code flow is redirected to a nop sled it will continue executing the effectless nops. At the end of the sled the true payload is added and execution will eventually hit this code. + The exploit uses a heap overflow to put a large nop sled in memory to decrease the accuracy needed in the initial redirection of code flow. A nop sled is a large section of contiguous instructions which do nothing. When code flow is redirected to a nop sled it will continue executing the effect-less nops. At the end of the sled the true payload is added and execution will eventually hit this code. A nop generator module was created for MIPS by creating a stream of random instructions which create no side-effects e.g. `sll $2, $2, 0` -### Heap address bruteforce +### Heap address brute force - The exploit uses a brute force approach to minimise problems with unpredictability in heap layout. The exploit itself is run multiple times, each time targetting a different point in the heap with the change of execution flow. If all goes correctly, the nop sled will be hit and code execution will follow. If the nop sled is missed, the Samba process is likely to crash, which is generally not a problem as a new instance is forked for each incoming connection. In the event of a crash, a new heap address is chosen and exploitation is attempted again. + The exploit uses a brute force approach to minimize problems with unpredictability in heap layout. The exploit itself is run multiple times, each time targeting a different point in the heap with the change of execution flow. If all goes correctly, the nop sled will be hit and code execution will follow. If the nop sled is missed, the Samba process is likely to crash, which is generally not a problem as a new instance is forked for each incoming connection. In the event of a crash, a new heap address is chosen and exploitation is attempted again. - When porting the exploit to a new system, the approximate heap layout must be known in order to suitably attempt exploitation across all of the possible heap locations. As the MIPS port targetted a specific router, the heap layout was determined by examining the ranges identified in _/proc//maps_ + When porting the exploit to a new system, the approximate heap layout must be known in order to suitably attempt exploitation across all of the possible heap locations. As the MIPS port targeted a specific router, the heap layout was determined by examining the ranges identified in _/proc//maps_ ## Scenarios