diff options
Diffstat (limited to 'NorthstarDLL/exploitfixes_utf8parser.cpp')
| -rw-r--r-- | NorthstarDLL/exploitfixes_utf8parser.cpp | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/NorthstarDLL/exploitfixes_utf8parser.cpp b/NorthstarDLL/exploitfixes_utf8parser.cpp new file mode 100644 index 00000000..e2510765 --- /dev/null +++ b/NorthstarDLL/exploitfixes_utf8parser.cpp @@ -0,0 +1,200 @@ +#include "pch.h" + +AUTOHOOK_INIT() + +INT64(__fastcall* sub_F1320)(DWORD a1, char* a2); + +// Reimplementation of an exploitable UTF decoding function in titanfall +bool __fastcall CheckUTF8Valid(INT64* a1, DWORD* a2, char* strData) +{ + DWORD v3; // eax + char* v4; // rbx + char v5; // si + char* _strData; // rdi + char* v7; // rbp + char v11; // al + DWORD v12; // er9 + DWORD v13; // ecx + DWORD v14; // edx + DWORD v15; // er8 + int v16; // eax + DWORD v17; // er9 + int v18; // eax + DWORD v19; // er9 + DWORD v20; // ecx + int v21; // eax + int v22; // er9 + DWORD v23; // edx + int v24; // eax + int v25; // er9 + DWORD v26; // er9 + DWORD v27; // er10 + DWORD v28; // ecx + DWORD v29; // edx + DWORD v30; // er8 + int v31; // eax + DWORD v32; // er10 + int v33; // eax + DWORD v34; // er10 + DWORD v35; // ecx + int v36; // eax + int v37; // er10 + DWORD v38; // edx + int v39; // eax + int v40; // er10 + DWORD v41; // er10 + INT64 v43; // r8 + INT64 v44; // rdx + INT64 v45; // rcx + INT64 v46; // rax + INT64 v47; // rax + char v48; // al + INT64 v49; // r8 + INT64 v50; // rdx + INT64 v51; // rcx + INT64 v52; // rax + INT64 v53; // rax + + v3 = a2[2]; + v4 = (char*)(a1[1] + *a2); + v5 = 0; + _strData = strData; + v7 = &v4[*((UINT16*)a2 + 2)]; + if (v3 >= 2) + { + ++v4; + --v7; + if (v3 != 2) + { + while (1) + { + if (!MemoryAddress(v4).IsMemoryReadable(1)) + return false; // INVALID + + v11 = *v4++; // crash potential + if (v11 != 92) + goto LABEL_6; + v11 = *v4++; + if (v11 == 110) + break; + switch (v11) + { + case 't': + v11 = 9; + goto LABEL_6; + case 'r': + v11 = 13; + goto LABEL_6; + case 'b': + v11 = 8; + goto LABEL_6; + case 'f': + v11 = 12; + goto LABEL_6; + } + if (v11 != 117) + goto LABEL_6; + v12 = *v4 | 0x20; + v13 = v4[1] | 0x20; + v14 = v4[2] | 0x20; + v15 = v4[3] | 0x20; + v16 = 87; + if (v12 <= 0x39) + v16 = 48; + v17 = v12 - v16; + v18 = 87; + v19 = v17 << 12; + if (v13 <= 0x39) + v18 = 48; + v20 = v13 - v18; + v21 = 87; + v22 = (v20 << 8) | v19; + if (v14 <= 0x39) + v21 = 48; + v23 = v14 - v21; + v24 = 87; + v25 = (16 * v23) | v22; + if (v15 <= 0x39) + v24 = 48; + v4 += 4; + v26 = (v15 - v24) | v25; + if (v26 - 55296 <= 0x7FF) + { + if (v26 >= 0xDC00) + return true; + if (*v4 != 92 || v4[1] != 117) + return true; + + v27 = v4[2] | 0x20; + v28 = v4[3] | 0x20; + v29 = v4[4] | 0x20; + v30 = v4[5] | 0x20; + v31 = 87; + if (v27 <= 0x39) + v31 = 48; + v32 = v27 - v31; + v33 = 87; + v34 = v32 << 12; + if (v28 <= 0x39) + v33 = 48; + v35 = v28 - v33; + v36 = 87; + v37 = (v35 << 8) | v34; + if (v29 <= 0x39) + v36 = 48; + v38 = v29 - v36; + v39 = 87; + v40 = (16 * v38) | v37; + if (v30 <= 0x39) + v39 = 48; + v4 += 6; + v41 = ((v30 - v39) | v40) - 56320; + if (v41 > 0x3FF) + return true; + v26 = v41 | ((v26 - 55296) << 10); + } + _strData += (DWORD)sub_F1320(v26, _strData); + LABEL_7: + if (v4 == v7) + goto LABEL_48; + } + v11 = 10; + LABEL_6: + v5 |= v11; + *_strData++ = v11; + goto LABEL_7; + } + } +LABEL_48: + return true; +} + +// prevent utf8 parser from crashing when provided bad data, which can be sent through user-controlled openinvites +// clang-format off +AUTOHOOK(Rson_ParseUTF8, engine.dll + 0xEF670, +bool, __fastcall, (INT64* a1, DWORD* a2, char* strData)) // 48 89 5C 24 ? 48 89 6C 24 ? 48 89 74 24 ? 57 41 54 41 55 41 56 41 57 48 83 EC 20 8B 1A +// clang-format on +{ + static void* targetRetAddr = CModule("engine.dll").FindPattern("84 C0 75 2C 49 8B 16"); + + // only call if we're parsing utf8 data from the network (i.e. communities), otherwise we get perf issues + void* pReturnAddress = +#ifdef _MSC_VER + _ReturnAddress() +#else + __builtin_return_address(0) +#endif + ; + + if (pReturnAddress == targetRetAddr && !CheckUTF8Valid(a1, a2, strData)) + return false; + + return Rson_ParseUTF8(a1, a2, strData); +} + +ON_DLL_LOAD("engine.dll", EngineExploitFixes_UTF8Parser, (CModule module)) +{ + AUTOHOOK_DISPATCH() + + sub_F1320 = module.FindPattern("83 F9 7F 77 08 88 0A").As<INT64(__fastcall*)(DWORD, char*)>(); +} |