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-rw-r--r--NorthstarDLL/shared/exploit_fixes/exploitfixes.cpp458
-rw-r--r--NorthstarDLL/shared/exploit_fixes/exploitfixes_lzss.cpp79
-rw-r--r--NorthstarDLL/shared/exploit_fixes/exploitfixes_utf8parser.cpp200
-rw-r--r--NorthstarDLL/shared/exploit_fixes/ns_limits.cpp298
-rw-r--r--NorthstarDLL/shared/exploit_fixes/ns_limits.h51
5 files changed, 1086 insertions, 0 deletions
diff --git a/NorthstarDLL/shared/exploit_fixes/exploitfixes.cpp b/NorthstarDLL/shared/exploit_fixes/exploitfixes.cpp
new file mode 100644
index 00000000..e4430fd4
--- /dev/null
+++ b/NorthstarDLL/shared/exploit_fixes/exploitfixes.cpp
@@ -0,0 +1,458 @@
+#include "pch.h"
+#include "core/convar/cvar.h"
+#include "ns_limits.h"
+#include "dedicated/dedicated.h"
+#include "core/tier0.h"
+#include "engine/r2engine.h"
+#include "client/r2client.h"
+#include "core/math/vector.h"
+
+AUTOHOOK_INIT()
+
+ConVar* Cvar_ns_exploitfixes_log;
+ConVar* Cvar_ns_should_log_all_clientcommands;
+
+ConVar* Cvar_sv_cheats;
+
+#define BLOCKED_INFO(s) \
+ ( \
+ [=]() -> bool \
+ { \
+ if (Cvar_ns_exploitfixes_log->GetBool()) \
+ { \
+ std::stringstream stream; \
+ stream << "ExploitFixes.cpp: " << BLOCK_PREFIX << s; \
+ spdlog::error(stream.str()); \
+ } \
+ return false; \
+ }())
+
+// block bad netmessages
+// Servers can literally request a screenshot from any client, yeah no
+// clang-format off
+AUTOHOOK(CLC_Screenshot_WriteToBuffer, engine.dll + 0x22AF20,
+bool, __fastcall, (void* thisptr, void* buffer)) // 48 89 5C 24 ? 57 48 83 EC 20 8B 42 10
+// clang-format on
+{
+ return false;
+}
+
+// clang-format off
+AUTOHOOK(CLC_Screenshot_ReadFromBuffer, engine.dll + 0x221F00,
+bool, __fastcall, (void* thisptr, void* buffer)) // 48 89 5C 24 ? 48 89 6C 24 ? 48 89 74 24 ? 57 48 83 EC 20 48 8B DA 48 8B 52 38
+// clang-format on
+{
+ return false;
+}
+
+// This is unused ingame and a big client=>server=>client exploit vector
+// clang-format off
+AUTOHOOK(Base_CmdKeyValues_ReadFromBuffer, engine.dll + 0x220040,
+bool, __fastcall, (void* thisptr, void* buffer)) // 40 55 48 81 EC ? ? ? ? 48 8D 6C 24 ? 48 89 5D 70
+// clang-format on
+{
+ return false;
+}
+
+// clang-format off
+AUTOHOOK(CClient_ProcessSetConVar, engine.dll + 0x75CF0,
+bool, __fastcall, (void* pMsg)) // 48 8B D1 48 8B 49 18 48 8B 01 48 FF 60 10
+// clang-format on
+{
+
+ constexpr int ENTRY_STR_LEN = 260;
+ struct SetConVarEntry
+ {
+ char name[ENTRY_STR_LEN];
+ char val[ENTRY_STR_LEN];
+ };
+
+ struct NET_SetConVar
+ {
+ void* vtable;
+ void* unk1;
+ void* unk2;
+ void* m_pMessageHandler;
+ SetConVarEntry* m_ConVars; // convar entry array
+ void* unk5; // these 2 unks are just vector capacity or whatever
+ void* unk6;
+ int m_ConVars_count; // amount of cvar entries in array (this will not be out of bounds)
+ };
+
+ auto msg = (NET_SetConVar*)pMsg;
+ bool bIsServerFrame = Tier0::ThreadInServerFrameThread();
+
+ std::string BLOCK_PREFIX =
+ std::string {"NET_SetConVar ("} + (bIsServerFrame ? "server" : "client") + "): Blocked dangerous/invalid msg: ";
+
+ if (bIsServerFrame)
+ {
+ constexpr int SETCONVAR_SANITY_AMOUNT_LIMIT = 69;
+ if (msg->m_ConVars_count < 1 || msg->m_ConVars_count > SETCONVAR_SANITY_AMOUNT_LIMIT)
+ {
+ return BLOCKED_INFO("Invalid m_ConVars_count (" << msg->m_ConVars_count << ")");
+ }
+ }
+
+ for (int i = 0; i < msg->m_ConVars_count; i++)
+ {
+ auto entry = msg->m_ConVars + i;
+
+ // Safety check for memory access
+ if (MemoryAddress(entry).IsMemoryReadable(sizeof(*entry)))
+ {
+ // Find null terminators
+ bool nameValid = false, valValid = false;
+ for (int i = 0; i < ENTRY_STR_LEN; i++)
+ {
+ if (!entry->name[i])
+ nameValid = true;
+ if (!entry->val[i])
+ valValid = true;
+ }
+
+ if (!nameValid || !valValid)
+ return BLOCKED_INFO("Missing null terminators");
+
+ ConVar* pVar = R2::g_pCVar->FindVar(entry->name);
+
+ if (pVar)
+ {
+ memcpy(
+ entry->name,
+ pVar->m_ConCommandBase.m_pszName,
+ strlen(pVar->m_ConCommandBase.m_pszName) + 1); // Force name to match case
+
+ int iFlags = bIsServerFrame ? FCVAR_USERINFO : FCVAR_REPLICATED;
+ if (!pVar->IsFlagSet(iFlags))
+ return BLOCKED_INFO(
+ "Invalid flags (" << std::hex << "0x" << pVar->m_ConCommandBase.m_nFlags << "), var is " << entry->name);
+ }
+ }
+ else
+ {
+ return BLOCKED_INFO("Unreadable memory at " << (void*)entry); // Not risking that one, they all gotta be readable
+ }
+ }
+
+ return CClient_ProcessSetConVar(msg);
+}
+
+// prevent invalid user CMDs
+// clang-format off
+AUTOHOOK(CClient_ProcessUsercmds, engine.dll + 0x1040F0,
+bool, __fastcall, (void* thisptr, void* pMsg)) // 40 55 56 48 83 EC 58
+// clang-format on
+{
+ struct CLC_Move
+ {
+ BYTE gap0[24];
+ void* m_pMessageHandler;
+ int m_nBackupCommands;
+ int m_nNewCommands;
+ int m_nLength;
+ // bf_read m_DataIn;
+ // bf_write m_DataOut;
+ };
+
+ auto msg = (CLC_Move*)pMsg;
+
+ const char* BLOCK_PREFIX = "ProcessUserCmds: ";
+
+ if (msg->m_nBackupCommands < 0)
+ {
+ return BLOCKED_INFO("Invalid m_nBackupCommands (" << msg->m_nBackupCommands << ")");
+ }
+
+ if (msg->m_nNewCommands < 0)
+ {
+ return BLOCKED_INFO("Invalid m_nNewCommands (" << msg->m_nNewCommands << ")");
+ }
+
+ if (msg->m_nLength <= 0)
+ return BLOCKED_INFO("Invalid message length (" << msg->m_nLength << ")");
+
+ return CClient_ProcessUsercmds(thisptr, pMsg);
+}
+
+// clang-format off
+AUTOHOOK(ReadUsercmd, server.dll + 0x2603F0,
+void, __fastcall, (void* buf, void* pCmd_move, void* pCmd_from)) // 4C 89 44 24 ? 53 55 56 57
+// clang-format on
+{
+ // Let normal usercmd read happen first, it's safe
+ ReadUsercmd(buf, pCmd_move, pCmd_from);
+
+ // Now let's make sure the CMD we read isnt messed up to prevent numerous exploits (including server crashing)
+ struct alignas(4) SV_CUserCmd
+ {
+ DWORD command_number;
+ DWORD tick_count;
+ float command_time;
+ Vector3 worldViewAngles;
+ BYTE gap18[4];
+ Vector3 localViewAngles;
+ Vector3 attackangles;
+ Vector3 move;
+ DWORD buttons;
+ BYTE impulse;
+ short weaponselect;
+ DWORD meleetarget;
+ BYTE gap4C[24];
+ char headoffset;
+ BYTE gap65[11];
+ Vector3 cameraPos;
+ Vector3 cameraAngles;
+ BYTE gap88[4];
+ int tickSomething;
+ DWORD dword90;
+ DWORD predictedServerEventAck;
+ DWORD dword98;
+ float frameTime;
+ };
+
+ auto cmd = (SV_CUserCmd*)pCmd_move;
+ auto fromCmd = (SV_CUserCmd*)pCmd_from;
+
+ std::string BLOCK_PREFIX =
+ "ReadUsercmd (command_number delta: " + std::to_string(cmd->command_number - fromCmd->command_number) + "): ";
+
+ // fix invalid player angles
+ cmd->worldViewAngles.MakeValid();
+ cmd->attackangles.MakeValid();
+ cmd->localViewAngles.MakeValid();
+
+ // Fix invalid camera angles
+ cmd->cameraPos.MakeValid();
+ cmd->cameraAngles.MakeValid();
+
+ // Fix invaid movement vector
+ cmd->move.MakeValid();
+
+ if (cmd->frameTime <= 0 || cmd->tick_count == 0 || cmd->command_time <= 0)
+ {
+ BLOCKED_INFO(
+ "Bogus cmd timing (tick_count: " << cmd->tick_count << ", frameTime: " << cmd->frameTime
+ << ", commandTime : " << cmd->command_time << ")");
+ goto INVALID_CMD; // No simulation of bogus-timed cmds
+ }
+
+ return;
+
+INVALID_CMD:
+
+ // Fix any gameplay-affecting cmd properties
+ // NOTE: Currently tickcount/frametime is set to 0, this ~shouldn't~ cause any problems
+ cmd->worldViewAngles = cmd->localViewAngles = cmd->attackangles = cmd->cameraAngles = {0, 0, 0};
+ cmd->tick_count = cmd->frameTime = 0;
+ cmd->move = cmd->cameraPos = {0, 0, 0};
+ cmd->buttons = 0;
+ cmd->meleetarget = 0;
+}
+
+// ensure that GetLocalBaseClient().m_bRestrictServerCommands is set correctly, which the return value of this function controls
+// this is IsValveMod in source, but we're making it IsRespawnMod now since valve didn't make this one
+// clang-format off
+AUTOHOOK(IsRespawnMod, engine.dll + 0x1C6360,
+bool, __fastcall, (const char* pModName)) // 48 83 EC 28 48 8B 0D ? ? ? ? 48 8D 15 ? ? ? ? E8 ? ? ? ? 85 C0 74 63
+// clang-format on
+{
+ // somewhat temp, store the modname here, since we don't have a proper ptr in engine to it rn
+ int iSize = strlen(pModName);
+ R2::g_pModName = new char[iSize + 1];
+ strcpy(R2::g_pModName, pModName);
+
+ return (!strcmp("r2", pModName) || !strcmp("r1", pModName)) && !Tier0::CommandLine()->CheckParm("-norestrictservercommands");
+}
+
+// ratelimit stringcmds, and prevent remote clients from calling commands that they shouldn't
+bool (*CCommand__Tokenize)(CCommand& self, const char* pCommandString, R2::cmd_source_t commandSource);
+
+// clang-format off
+AUTOHOOK(CGameClient__ExecuteStringCommand, engine.dll + 0x1022E0,
+bool, __fastcall, (R2::CBaseClient* self, uint32_t unknown, const char* pCommandString))
+// clang-format on
+{
+ if (Cvar_ns_should_log_all_clientcommands->GetBool())
+ spdlog::info("player {} (UID: {}) sent command: \"{}\"", self->m_Name, self->m_UID, pCommandString);
+
+ if (!g_pServerLimits->CheckStringCommandLimits(self))
+ {
+ R2::CBaseClient__Disconnect(self, 1, "Sent too many stringcmd commands");
+ return false;
+ }
+
+ // verify the command we're trying to execute is FCVAR_GAMEDLL_FOR_REMOTE_CLIENTS, if it's a concommand
+ char* commandBuf[1040]; // assumedly this is the size of CCommand since we don't have an actual constructor
+ memset(commandBuf, 0, sizeof(commandBuf));
+ CCommand tempCommand = *(CCommand*)&commandBuf;
+
+ if (!CCommand__Tokenize(tempCommand, pCommandString, R2::cmd_source_t::kCommandSrcCode) || !tempCommand.ArgC())
+ return false;
+
+ ConCommand* command = R2::g_pCVar->FindCommand(tempCommand.Arg(0));
+
+ // if the command doesn't exist pass it on to ExecuteStringCommand for script clientcommands and stuff
+ if (command && !command->IsFlagSet(FCVAR_GAMEDLL_FOR_REMOTE_CLIENTS))
+ {
+ // ensure FCVAR_GAMEDLL concommands without FCVAR_GAMEDLL_FOR_REMOTE_CLIENTS can't be executed by remote clients
+ if (IsDedicatedServer())
+ return false;
+
+ if (strcmp(self->m_UID, R2::g_pLocalPlayerUserID))
+ return false;
+ }
+
+ // check for and block abusable legacy portal 2 commands
+ // these aren't actually concommands weirdly enough, they seem to just be hardcoded
+ if (!Cvar_sv_cheats->GetBool())
+ {
+ constexpr const char* blockedCommands[] = {
+ "emit", // Sound-playing exploit (likely for Portal 2 coop devs testing splitscreen sound or something)
+
+ // These both execute a command for every single entity for some reason, nice one valve
+ "pre_go_to_hub",
+ "pre_go_to_calibration",
+
+ "end_movie", // Calls "__MovieFinished" script function, not sure exactly what this does but it certainly isn't needed
+ "load_recent_checkpoint" // This is the instant-respawn exploit, literally just calls RespawnPlayer()
+ };
+
+ int iCmdLength = strlen(tempCommand.Arg(0));
+
+ bool bIsBadCommand = false;
+ for (auto& blockedCommand : blockedCommands)
+ {
+ if (iCmdLength != strlen(blockedCommand))
+ continue;
+
+ for (int i = 0; tempCommand.Arg(0)[i]; i++)
+ if (tolower(tempCommand.Arg(0)[i]) != blockedCommand[i])
+ goto NEXT_COMMAND; // break out of this loop, then go to next command
+
+ // this is a command we need to block
+ return false;
+ NEXT_COMMAND:;
+ }
+ }
+
+ return CGameClient__ExecuteStringCommand(self, unknown, pCommandString);
+}
+
+// prevent clients from crashing servers through overflowing CNetworkStringTableContainer::WriteBaselines
+bool bWasWritingStringTableSuccessful;
+
+// clang-format off
+AUTOHOOK(CBaseClient__SendServerInfo, engine.dll + 0x104FB0,
+void, __fastcall, (void* self))
+// clang-format on
+{
+ bWasWritingStringTableSuccessful = true;
+ CBaseClient__SendServerInfo(self);
+ if (!bWasWritingStringTableSuccessful)
+ R2::CBaseClient__Disconnect(
+ self, 1, "Overflowed CNetworkStringTableContainer::WriteBaselines, try restarting your client and reconnecting");
+}
+
+// return null when GetEntByIndex is passed an index >= 0x4000
+// this is called from exactly 1 script clientcommand that can be given an arbitrary index, and going above 0x4000 crashes
+// clang-format off
+AUTOHOOK(GetEntByIndex, server.dll + 0x2A8A50,
+void*, __fastcall, (int i))
+// clang-format on
+{
+ const int MAX_ENT_IDX = 0x4000;
+
+ if (i >= MAX_ENT_IDX)
+ {
+ spdlog::warn("GetEntByIndex {} is out of bounds (max {})", i, MAX_ENT_IDX);
+ return nullptr;
+ }
+
+ return GetEntByIndex(i);
+}
+// clang-format off
+AUTOHOOK(CL_CopyExistingEntity, engine.dll + 0x6F940,
+bool, __fastcall, (void* a1))
+// clang-format on
+{
+ struct CEntityReadInfo
+ {
+ BYTE gap[40];
+ int nNewEntity;
+ };
+
+ CEntityReadInfo* pReadInfo = (CEntityReadInfo*)a1;
+ if (pReadInfo->nNewEntity >= 0x1000 || pReadInfo->nNewEntity < 0)
+ {
+ // Value isn't sanitized in release builds for
+ // every game powered by the Source Engine 1
+ // causing read/write outside of array bounds.
+ // This defect has let to the achievement of a
+ // full-chain RCE exploit. We hook and perform
+ // sanity checks for the value of m_nNewEntity
+ // here to prevent this behavior from happening.
+ return false;
+ }
+
+ return CL_CopyExistingEntity(a1);
+}
+
+ON_DLL_LOAD("engine.dll", EngineExploitFixes, (CModule module))
+{
+ AUTOHOOK_DISPATCH_MODULE(engine.dll)
+
+ CCommand__Tokenize = module.Offset(0x418380).As<bool (*)(CCommand&, const char*, R2::cmd_source_t)>();
+
+ // allow client/ui to run clientcommands despite restricting servercommands
+ module.Offset(0x4FB65).Patch("EB 11");
+ module.Offset(0x4FBAC).Patch("EB 16");
+
+ // patch to set bWasWritingStringTableSuccessful in CNetworkStringTableContainer::WriteBaselines if it fails
+ {
+ MemoryAddress writeAddress(&bWasWritingStringTableSuccessful - module.Offset(0x234EDC).m_nAddress);
+
+ MemoryAddress addr = module.Offset(0x234ED2);
+ addr.Patch("C7 05");
+ addr.Offset(2).Patch((BYTE*)&writeAddress, sizeof(writeAddress));
+
+ addr.Offset(6).Patch("00 00 00 00");
+
+ addr.Offset(10).NOP(5);
+ }
+}
+
+ON_DLL_LOAD_RELIESON("server.dll", ServerExploitFixes, ConVar, (CModule module))
+{
+ AUTOHOOK_DISPATCH_MODULE(server.dll)
+
+ // ret at the start of CServerGameClients::ClientCommandKeyValues as it has no benefit and is forwarded to client (i.e. security issue)
+ // this prevents the attack vector of client=>server=>client, however server=>client also has clientside patches
+ module.Offset(0x153920).Patch("C3");
+
+ // Dumb ANTITAMPER patches (they negatively impact performance and security)
+ constexpr const char* ANTITAMPER_EXPORTS[] = {
+ "ANTITAMPER_SPOTCHECK_CODEMARKER",
+ "ANTITAMPER_TESTVALUE_CODEMARKER",
+ "ANTITAMPER_TRIGGER_CODEMARKER",
+ };
+
+ // Prevent these from actually doing anything
+ for (auto exportName : ANTITAMPER_EXPORTS)
+ {
+ MemoryAddress exportAddr = module.GetExport(exportName);
+ if (exportAddr)
+ {
+ // Just return, none of them have any args or are userpurge
+ exportAddr.Patch("C3");
+ spdlog::info("Patched AntiTamper function export \"{}\"", exportName);
+ }
+ }
+
+ Cvar_ns_exploitfixes_log =
+ new ConVar("ns_exploitfixes_log", "1", FCVAR_GAMEDLL, "Whether to log whenever ExploitFixes.cpp blocks/corrects something");
+ Cvar_ns_should_log_all_clientcommands =
+ new ConVar("ns_should_log_all_clientcommands", "0", FCVAR_NONE, "Whether to log all clientcommands");
+
+ Cvar_sv_cheats = R2::g_pCVar->FindVar("sv_cheats");
+}
diff --git a/NorthstarDLL/shared/exploit_fixes/exploitfixes_lzss.cpp b/NorthstarDLL/shared/exploit_fixes/exploitfixes_lzss.cpp
new file mode 100644
index 00000000..4205133a
--- /dev/null
+++ b/NorthstarDLL/shared/exploit_fixes/exploitfixes_lzss.cpp
@@ -0,0 +1,79 @@
+#include "pch.h"
+
+AUTOHOOK_INIT()
+
+static constexpr int LZSS_LOOKSHIFT = 4;
+
+struct lzss_header_t
+{
+ unsigned int id;
+ unsigned int actualSize;
+};
+
+// Rewrite of CLZSS::SafeUncompress to fix a vulnerability where malicious compressed payloads could cause the decompressor to try to read
+// out of the bounds of the output buffer.
+// clang-format off
+AUTOHOOK(CLZSS__SafeDecompress, engine.dll + 0x432A10,
+unsigned int, __fastcall, (void* self, const unsigned char* pInput, unsigned char* pOutput, unsigned int unBufSize))
+// clang-format on
+{
+ unsigned int totalBytes = 0;
+ int getCmdByte = 0;
+ int cmdByte = 0;
+
+ lzss_header_t header = *(lzss_header_t*)pInput;
+
+ if (!pInput || !header.actualSize || header.id != 0x53535A4C || header.actualSize > unBufSize)
+ return 0;
+
+ pInput += sizeof(lzss_header_t);
+
+ for (;;)
+ {
+ if (!getCmdByte)
+ cmdByte = *pInput++;
+
+ getCmdByte = (getCmdByte + 1) & 0x07;
+
+ if (cmdByte & 0x01)
+ {
+ int position = *pInput++ << LZSS_LOOKSHIFT;
+ position |= (*pInput >> LZSS_LOOKSHIFT);
+ position += 1;
+ int count = (*pInput++ & 0x0F) + 1;
+ if (count == 1)
+ break;
+
+ // Ensure reference chunk exists entirely within our buffer
+ if (position > totalBytes)
+ return 0;
+
+ totalBytes += count;
+ if (totalBytes > unBufSize)
+ return 0;
+
+ unsigned char* pSource = pOutput - position;
+ for (int i = 0; i < count; i++)
+ *pOutput++ = *pSource++;
+ }
+ else
+ {
+ totalBytes++;
+ if (totalBytes > unBufSize)
+ return 0;
+
+ *pOutput++ = *pInput++;
+ }
+ cmdByte = cmdByte >> 1;
+ }
+
+ if (totalBytes != header.actualSize)
+ return 0;
+
+ return totalBytes;
+}
+
+ON_DLL_LOAD("engine.dll", ExploitFixes_LZSS, (CModule module))
+{
+ AUTOHOOK_DISPATCH()
+}
diff --git a/NorthstarDLL/shared/exploit_fixes/exploitfixes_utf8parser.cpp b/NorthstarDLL/shared/exploit_fixes/exploitfixes_utf8parser.cpp
new file mode 100644
index 00000000..e2510765
--- /dev/null
+++ b/NorthstarDLL/shared/exploit_fixes/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*)>();
+}
diff --git a/NorthstarDLL/shared/exploit_fixes/ns_limits.cpp b/NorthstarDLL/shared/exploit_fixes/ns_limits.cpp
new file mode 100644
index 00000000..49f80bab
--- /dev/null
+++ b/NorthstarDLL/shared/exploit_fixes/ns_limits.cpp
@@ -0,0 +1,298 @@
+#include "pch.h"
+#include "ns_limits.h"
+#include "engine/hoststate.h"
+#include "client/r2client.h"
+#include "engine/r2engine.h"
+#include "server/r2server.h"
+#include "shared/maxplayers.h"
+#include "core/tier0.h"
+#include "core/math/vector.h"
+#include "server/auth/serverauthentication.h"
+
+AUTOHOOK_INIT()
+
+ServerLimitsManager* g_pServerLimits;
+
+// todo: make this work on higher timescales, also possibly disable when sv_cheats is set
+void ServerLimitsManager::RunFrame(double flCurrentTime, float flFrameTime)
+{
+ if (Cvar_sv_antispeedhack_enable->GetBool())
+ {
+ // for each player, set their usercmd processing budget for the frame to the last frametime for the server
+ for (int i = 0; i < R2::GetMaxPlayers(); i++)
+ {
+ R2::CBaseClient* player = &R2::g_pClientArray[i];
+
+ if (m_PlayerLimitData.find(player) != m_PlayerLimitData.end())
+ {
+ PlayerLimitData* pLimitData = &g_pServerLimits->m_PlayerLimitData[player];
+ if (pLimitData->flFrameUserCmdBudget < 0.016666667 * Cvar_sv_antispeedhack_maxtickbudget->GetFloat())
+ pLimitData->flFrameUserCmdBudget +=
+ fmax(flFrameTime, 0.016666667) * g_pServerLimits->Cvar_sv_antispeedhack_budgetincreasemultiplier->GetFloat();
+ }
+ }
+ }
+}
+
+void ServerLimitsManager::AddPlayer(R2::CBaseClient* player)
+{
+ PlayerLimitData limitData;
+ limitData.flFrameUserCmdBudget = 0.016666667 * Cvar_sv_antispeedhack_maxtickbudget->GetFloat();
+
+ m_PlayerLimitData.insert(std::make_pair(player, limitData));
+}
+
+void ServerLimitsManager::RemovePlayer(R2::CBaseClient* player)
+{
+ if (m_PlayerLimitData.find(player) != m_PlayerLimitData.end())
+ m_PlayerLimitData.erase(player);
+}
+
+bool ServerLimitsManager::CheckStringCommandLimits(R2::CBaseClient* player)
+{
+ if (CVar_sv_quota_stringcmdspersecond->GetInt() != -1)
+ {
+ // note: this isn't super perfect, legit clients can trigger it in lobby if they try, mostly good enough tho imo
+ if (Tier0::Plat_FloatTime() - m_PlayerLimitData[player].lastClientCommandQuotaStart >= 1.0)
+ {
+ // reset quota
+ m_PlayerLimitData[player].lastClientCommandQuotaStart = Tier0::Plat_FloatTime();
+ m_PlayerLimitData[player].numClientCommandsInQuota = 0;
+ }
+
+ m_PlayerLimitData[player].numClientCommandsInQuota++;
+ if (m_PlayerLimitData[player].numClientCommandsInQuota > CVar_sv_quota_stringcmdspersecond->GetInt())
+ {
+ // too many stringcmds, dc player
+ return false;
+ }
+ }
+
+ return true;
+}
+
+bool ServerLimitsManager::CheckChatLimits(R2::CBaseClient* player)
+{
+ if (Tier0::Plat_FloatTime() - m_PlayerLimitData[player].lastSayTextLimitStart >= 1.0)
+ {
+ m_PlayerLimitData[player].lastSayTextLimitStart = Tier0::Plat_FloatTime();
+ m_PlayerLimitData[player].sayTextLimitCount = 0;
+ }
+
+ if (m_PlayerLimitData[player].sayTextLimitCount >= Cvar_sv_max_chat_messages_per_sec->GetInt())
+ return false;
+
+ m_PlayerLimitData[player].sayTextLimitCount++;
+ return true;
+}
+
+// clang-format off
+AUTOHOOK(CNetChan__ProcessMessages, engine.dll + 0x2140A0,
+char, __fastcall, (void* self, void* buf))
+// clang-format on
+{
+ enum eNetChanLimitMode
+ {
+ NETCHANLIMIT_WARN,
+ NETCHANLIMIT_KICK
+ };
+
+ double startTime = Tier0::Plat_FloatTime();
+ char ret = CNetChan__ProcessMessages(self, buf);
+
+ // check processing limits, unless we're in a level transition
+ if (R2::g_pHostState->m_iCurrentState == R2::HostState_t::HS_RUN && Tier0::ThreadInServerFrameThread())
+ {
+ // player that sent the message
+ R2::CBaseClient* sender = *(R2::CBaseClient**)((char*)self + 368);
+
+ // if no sender, return
+ // relatively certain this is fine?
+ if (!sender || !g_pServerLimits->m_PlayerLimitData.count(sender))
+ return ret;
+
+ // reset every second
+ if (startTime - g_pServerLimits->m_PlayerLimitData[sender].lastNetChanProcessingLimitStart >= 1.0 ||
+ g_pServerLimits->m_PlayerLimitData[sender].lastNetChanProcessingLimitStart == -1.0)
+ {
+ g_pServerLimits->m_PlayerLimitData[sender].lastNetChanProcessingLimitStart = startTime;
+ g_pServerLimits->m_PlayerLimitData[sender].netChanProcessingLimitTime = 0.0;
+ }
+ g_pServerLimits->m_PlayerLimitData[sender].netChanProcessingLimitTime += (Tier0::Plat_FloatTime() * 1000) - (startTime * 1000);
+
+ if (g_pServerLimits->m_PlayerLimitData[sender].netChanProcessingLimitTime >=
+ g_pServerLimits->Cvar_net_chan_limit_msec_per_sec->GetInt())
+ {
+ spdlog::warn(
+ "Client {} hit netchan processing limit with {}ms of processing time this second (max is {})",
+ (char*)sender + 0x16,
+ g_pServerLimits->m_PlayerLimitData[sender].netChanProcessingLimitTime,
+ g_pServerLimits->Cvar_net_chan_limit_msec_per_sec->GetInt());
+
+ // never kick local player
+ if (g_pServerLimits->Cvar_net_chan_limit_mode->GetInt() != NETCHANLIMIT_WARN && strcmp(R2::g_pLocalPlayerUserID, sender->m_UID))
+ {
+ R2::CBaseClient__Disconnect(sender, 1, "Exceeded net channel processing limit");
+ return false;
+ }
+ }
+ }
+
+ return ret;
+}
+
+// clang-format off
+AUTOHOOK(ProcessConnectionlessPacket, engine.dll + 0x117800,
+bool, , (void* a1, R2::netpacket_t* packet))
+// clang-format on
+{
+ static const ConVar* Cvar_net_data_block_enabled = R2::g_pCVar->FindVar("net_data_block_enabled");
+
+ // don't ratelimit datablock packets as long as datablock is enabled
+ if (packet->adr.type == R2::NA_IP &&
+ (!(packet->data[4] == 'N' && Cvar_net_data_block_enabled->GetBool()) || !Cvar_net_data_block_enabled->GetBool()))
+ {
+ // bad lookup: optimise later tm
+ UnconnectedPlayerLimitData* sendData = nullptr;
+ for (UnconnectedPlayerLimitData& foundSendData : g_pServerLimits->m_UnconnectedPlayerLimitData)
+ {
+ if (!memcmp(packet->adr.ip, foundSendData.ip, 16))
+ {
+ sendData = &foundSendData;
+ break;
+ }
+ }
+
+ if (!sendData)
+ {
+ sendData = &g_pServerLimits->m_UnconnectedPlayerLimitData.emplace_back();
+ memcpy(sendData->ip, packet->adr.ip, 16);
+ }
+
+ if (Tier0::Plat_FloatTime() < sendData->timeoutEnd)
+ return false;
+
+ if (Tier0::Plat_FloatTime() - sendData->lastQuotaStart >= 1.0)
+ {
+ sendData->lastQuotaStart = Tier0::Plat_FloatTime();
+ sendData->packetCount = 0;
+ }
+
+ sendData->packetCount++;
+
+ if (sendData->packetCount >= g_pServerLimits->Cvar_sv_querylimit_per_sec->GetInt())
+ {
+ spdlog::warn(
+ "Client went over connectionless ratelimit of {} per sec with packet of type {}",
+ g_pServerLimits->Cvar_sv_querylimit_per_sec->GetInt(),
+ packet->data[4]);
+
+ // timeout for a minute
+ sendData->timeoutEnd = Tier0::Plat_FloatTime() + 60.0;
+ return false;
+ }
+ }
+
+ return ProcessConnectionlessPacket(a1, packet);
+}
+
+// this is weird and i'm not sure if it's correct, so not using for now
+/*AUTOHOOK(CBasePlayer__PhysicsSimulate, server.dll + 0x5A6E50, bool, __fastcall, (void* self, int a2, char a3))
+{
+ spdlog::info("CBasePlayer::PhysicsSimulate");
+ return CBasePlayer__PhysicsSimulate(self, a2, a3);
+}*/
+
+struct alignas(4) SV_CUserCmd
+{
+ DWORD command_number;
+ DWORD tick_count;
+ float command_time;
+ Vector3 worldViewAngles;
+ BYTE gap18[4];
+ Vector3 localViewAngles;
+ Vector3 attackangles;
+ Vector3 move;
+ DWORD buttons;
+ BYTE impulse;
+ short weaponselect;
+ DWORD meleetarget;
+ BYTE gap4C[24];
+ char headoffset;
+ BYTE gap65[11];
+ Vector3 cameraPos;
+ Vector3 cameraAngles;
+ BYTE gap88[4];
+ int tickSomething;
+ DWORD dword90;
+ DWORD predictedServerEventAck;
+ DWORD dword98;
+ float frameTime;
+};
+
+// clang-format off
+AUTOHOOK(CPlayerMove__RunCommand, server.dll + 0x5B8100,
+void, __fastcall, (void* self, R2::CBasePlayer* player, SV_CUserCmd* pUserCmd, uint64_t a4))
+// clang-format on
+{
+ if (g_pServerLimits->Cvar_sv_antispeedhack_enable->GetBool())
+ {
+ R2::CBaseClient* pClient = &R2::g_pClientArray[player->m_nPlayerIndex - 1];
+
+ if (g_pServerLimits->m_PlayerLimitData.find(pClient) != g_pServerLimits->m_PlayerLimitData.end())
+ {
+ PlayerLimitData* pLimitData = &g_pServerLimits->m_PlayerLimitData[pClient];
+
+ pLimitData->flFrameUserCmdBudget = fmax(0.0, pLimitData->flFrameUserCmdBudget - pUserCmd->frameTime);
+
+ if (pLimitData->flFrameUserCmdBudget <= 0.0)
+ {
+ spdlog::warn("player {} went over usercmd budget ({})", pClient->m_Name, pLimitData->flFrameUserCmdBudget);
+ return;
+ }
+ // else
+ // spdlog::info("{}: {}", pClient->m_Name, pLimitData->flFrameUserCmdBudget);
+ }
+ }
+
+ CPlayerMove__RunCommand(self, player, pUserCmd, a4);
+}
+
+ON_DLL_LOAD_RELIESON("engine.dll", ServerLimits, ConVar, (CModule module))
+{
+ AUTOHOOK_DISPATCH_MODULE(engine.dll)
+
+ g_pServerLimits = new ServerLimitsManager;
+
+ g_pServerLimits->CVar_sv_quota_stringcmdspersecond = new ConVar(
+ "sv_quota_stringcmdspersecond",
+ "60",
+ FCVAR_GAMEDLL,
+ "How many string commands per second clients are allowed to submit, 0 to disallow all string commands, -1 to disable");
+ g_pServerLimits->Cvar_net_chan_limit_mode =
+ new ConVar("net_chan_limit_mode", "0", FCVAR_GAMEDLL, "The mode for netchan processing limits: 0 = warn, 1 = kick");
+ g_pServerLimits->Cvar_net_chan_limit_msec_per_sec = new ConVar(
+ "net_chan_limit_msec_per_sec",
+ "100",
+ FCVAR_GAMEDLL,
+ "Netchannel processing is limited to so many milliseconds, abort connection if exceeding budget");
+ g_pServerLimits->Cvar_sv_querylimit_per_sec = new ConVar("sv_querylimit_per_sec", "15", FCVAR_GAMEDLL, "");
+ g_pServerLimits->Cvar_sv_max_chat_messages_per_sec = new ConVar("sv_max_chat_messages_per_sec", "5", FCVAR_GAMEDLL, "");
+ g_pServerLimits->Cvar_sv_antispeedhack_enable =
+ new ConVar("sv_antispeedhack_enable", "0", FCVAR_NONE, "whether to enable antispeedhack protections");
+ g_pServerLimits->Cvar_sv_antispeedhack_maxtickbudget = new ConVar(
+ "sv_antispeedhack_maxtickbudget",
+ "64",
+ FCVAR_GAMEDLL,
+ "Maximum number of client-issued usercmd ticks that can be replayed in packet loss conditions, 0 to allow no restrictions");
+ g_pServerLimits->Cvar_sv_antispeedhack_budgetincreasemultiplier = new ConVar(
+ "sv_antispeedhack_budgetincreasemultiplier",
+ "1.2",
+ FCVAR_GAMEDLL,
+ "Increase usercmd processing budget by tickinterval * value per tick");
+}
+
+ON_DLL_LOAD("server.dll", ServerLimitsServer, (CModule module))
+{
+ AUTOHOOK_DISPATCH_MODULE(server.dll)
+}
diff --git a/NorthstarDLL/shared/exploit_fixes/ns_limits.h b/NorthstarDLL/shared/exploit_fixes/ns_limits.h
new file mode 100644
index 00000000..bbc0a85f
--- /dev/null
+++ b/NorthstarDLL/shared/exploit_fixes/ns_limits.h
@@ -0,0 +1,51 @@
+#pragma once
+#include "engine/r2engine.h"
+#include "core/convar/convar.h"
+#include <unordered_map>
+
+struct PlayerLimitData
+{
+ double lastClientCommandQuotaStart = -1.0;
+ int numClientCommandsInQuota = 0;
+
+ double lastNetChanProcessingLimitStart = -1.0;
+ double netChanProcessingLimitTime = 0.0;
+
+ double lastSayTextLimitStart = -1.0;
+ int sayTextLimitCount = 0;
+
+ float flFrameUserCmdBudget = 0.0;
+};
+
+struct UnconnectedPlayerLimitData
+{
+ char ip[16];
+ double lastQuotaStart = 0.0;
+ int packetCount = 0;
+ double timeoutEnd = -1.0;
+};
+
+class ServerLimitsManager
+{
+ public:
+ ConVar* CVar_sv_quota_stringcmdspersecond;
+ ConVar* Cvar_net_chan_limit_mode;
+ ConVar* Cvar_net_chan_limit_msec_per_sec;
+ ConVar* Cvar_sv_querylimit_per_sec;
+ ConVar* Cvar_sv_max_chat_messages_per_sec;
+ ConVar* Cvar_sv_antispeedhack_enable;
+ ConVar* Cvar_sv_antispeedhack_maxtickbudget;
+ ConVar* Cvar_sv_antispeedhack_budgetincreasemultiplier;
+
+ std::unordered_map<R2::CBaseClient*, PlayerLimitData> m_PlayerLimitData;
+ std::vector<UnconnectedPlayerLimitData> m_UnconnectedPlayerLimitData;
+
+ public:
+ void RunFrame(double flCurrentTime, float flFrameTime);
+ void AddPlayer(R2::CBaseClient* player);
+ void RemovePlayer(R2::CBaseClient* player);
+ bool CheckStringCommandLimits(R2::CBaseClient* player);
+ bool CheckChatLimits(R2::CBaseClient* player);
+};
+
+extern ServerLimitsManager* g_pServerLimits;