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authorJack <66967891+ASpoonPlaysGames@users.noreply.github.com>2023-12-27 00:32:01 +0000
committerGitHub <noreply@github.com>2023-12-27 01:32:01 +0100
commitf5ab6fb5e8be7b73e6003d4145081d5e0c0ce287 (patch)
tree90f2c6a4885dbd181799e2325cf33588697674e1 /NorthstarDLL/shared/exploit_fixes/exploitfixes.cpp
parentbb8ed59f6891b1196c5f5bbe7346cd171c8215fa (diff)
downloadNorthstarLauncher-f5ab6fb5e8be7b73e6003d4145081d5e0c0ce287.tar.gz
NorthstarLauncher-f5ab6fb5e8be7b73e6003d4145081d5e0c0ce287.zip
Folder restructuring from primedev (#624)v1.21.2-rc3v1.21.2
Copies of over the primedev folder structure for easier cherry-picking of further changes Co-authored-by: F1F7Y <filip.bartos07@proton.me>
Diffstat (limited to 'NorthstarDLL/shared/exploit_fixes/exploitfixes.cpp')
-rw-r--r--NorthstarDLL/shared/exploit_fixes/exploitfixes.cpp461
1 files changed, 0 insertions, 461 deletions
diff --git a/NorthstarDLL/shared/exploit_fixes/exploitfixes.cpp b/NorthstarDLL/shared/exploit_fixes/exploitfixes.cpp
deleted file mode 100644
index 8064d5ac..00000000
--- a/NorthstarDLL/shared/exploit_fixes/exploitfixes.cpp
+++ /dev/null
@@ -1,461 +0,0 @@
-#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"
-#include "core/vanilla.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
-{
- if (g_pVanillaCompatibility->GetVanillaCompatibility())
- return CLC_Screenshot_WriteToBuffer(thisptr, buffer);
- 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
-{
- if (g_pVanillaCompatibility->GetVanillaCompatibility())
- return CLC_Screenshot_ReadFromBuffer(thisptr, buffer);
- 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 = 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 (CMemoryAddress(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 = 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);
- g_pModName = new char[iSize + 1];
- strcpy(g_pModName, pModName);
-
- if (g_pVanillaCompatibility->GetVanillaCompatibility())
- return false;
-
- return (!strcmp("r2", pModName) || !strcmp("r1", pModName)) && !CommandLine()->CheckParm("-norestrictservercommands");
-}
-
-// ratelimit stringcmds, and prevent remote clients from calling commands that they shouldn't
-// clang-format off
-AUTOHOOK(CGameClient__ExecuteStringCommand, engine.dll + 0x1022E0,
-bool, __fastcall, (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))
- {
- 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, cmd_source_t::kCommandSrcCode) || !tempCommand.ArgC())
- return false;
-
- ConCommand* command = 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, 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)
- 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)
-
- // 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
- {
- CMemoryAddress writeAddress(&bWasWritingStringTableSuccessful - module.Offset(0x234EDC).m_nAddress);
-
- CMemoryAddress 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)
- {
- CMemoryAddress 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 = g_pCVar->FindVar("sv_cheats");
-}