diff --git a/authenc.cpp b/authenc.cpp
index bb6cf2c0..040a8063 100644
--- a/authenc.cpp
+++ b/authenc.cpp
@@ -10,10 +10,18 @@ NAMESPACE_BEGIN(CryptoPP)
 
 void AuthenticatedSymmetricCipherBase::AuthenticateData(const byte *input, size_t len)
 {
+	// UBsan finding with -std=c++03 using memcpy
+	CRYPTOPP_ASSERT(input && len);
+	if(!input || !len) return;
+
 	unsigned int blockSize = AuthenticationBlockSize();
 	unsigned int &num = m_bufferedDataLength;
 	byte* data = m_buffer.begin();
 
+	// UBsan finding with -std=c++03 using memcpy
+	CRYPTOPP_ASSERT(data);
+	if(!data) return;
+
 	if (num != 0)	// process left over data
 	{
 		if (num+len >= blockSize)