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dt: Explain client crash reason when malicious server sends CUtlVector length out of allowed range #1512

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dt: Explain client crash reason when malicious server sends CUtlVector length out of allowed range #1512

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6 changes: 5 additions & 1 deletion src/public/dt_utlvector_recv.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -36,7 +36,11 @@ void RecvProxy_UtlVectorLength( const CRecvProxyData *pData, void *pStruct, void
// to write arbitrary data to out of bounds memory.
// There isn't much we can do at this point - we're deep in the networking stack, it's hard to recover
// gracefully and we shouldn't be talking to this server anymore.
// So we crash.
//
// So we notify client.
Error("Server send utlvector length value %d which is not in range [%d...%d]. Crashing client to prevent RCE...\n",
pData->m_Value.m_Int, 0, pExtra->m_nMaxElements);
// And crash.
*(int *) 1 = 2;
}
pExtra->m_ResizeFn( pStruct, pExtra->m_Offset, pData->m_Value.m_Int );
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