fix index out of range (DoS) in txn unmarshalling (umbracle#203)

dangfuyang · May 27, 2022 · 37ddc01 · 37ddc01
1 parent c1d8327
commit 37ddc01
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/structs_marshal_rlp.go b/structs_marshal_rlp.go
@@ -84,6 +84,9 @@ func (t *Transaction) MarshalRLPWith(arena *fastrlp.Arena) (*fastrlp.Value, erro
 func (t *Transaction) UnmarshalRLP(buf []byte) error {
 	t.Hash = BytesToHash(Keccak256(buf))
 
+	if len(buf) < 1 {
+		return fmt.Errorf("expecting 1 byte but 0 byte provided")
+	}
 	if buf[0] <= 0x7f {
 		// it includes a type byte
 		switch typ := buf[0]; typ {