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Diffstat (limited to 'NorthstarDLL/exploitfixes_utf8parser.cpp')
-rw-r--r--NorthstarDLL/exploitfixes_utf8parser.cpp200
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*)>();
+}