From a753911f0005fa67d0d09f8ef81e6b37eeb49d08 Mon Sep 17 00:00:00 2001
From: Jun Kim <64379343+junkim012@users.noreply.github.com>
Date: Fri, 20 Dec 2024 13:56:41 -0500
Subject: [PATCH] fix: L-02 check for receiver or target teller being zero
 address

---
 .../Roles/CrossChain/MultiChainTellerBase.sol  | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/base/Roles/CrossChain/MultiChainTellerBase.sol b/src/base/Roles/CrossChain/MultiChainTellerBase.sol
index 2f47905..4880ffc 100644
--- a/src/base/Roles/CrossChain/MultiChainTellerBase.sol
+++ b/src/base/Roles/CrossChain/MultiChainTellerBase.sol
@@ -14,6 +14,8 @@ struct Chain {
 error MultiChainTellerBase_MessagesNotAllowedFrom(uint32 chainSelector);
 error MultiChainTellerBase_MessagesNotAllowedFromSender(uint256 chainSelector, address sender);
 error MultiChainTellerBase_MessagesNotAllowedTo(uint256 chainSelector);
+error MultiChainTellerBase_TargetTellerIsZeroAddress();
+error MultiChainTellerBase_DestinationChainReceiverIsZeroAddress();
 error MultiChainTellerBase_ZeroMessageGasLimit();
 error MultiChainTellerBase_GasLimitExceeded();
 error MultiChainTellerBase_GasTooLow();
@@ -172,15 +174,25 @@ abstract contract MultiChainTellerBase is CrossChainTellerBase {
      * @param data bridge data
      */
     function _beforeBridge(BridgeData calldata data) internal override {
-        if (!selectorToChains[data.chainSelector].allowMessagesTo) {
+        Chain chain = selectorToChains[data.chainSelector];
+
+        if (!chain.allowMessagesTo) {
             revert MultiChainTellerBase_MessagesNotAllowedTo(data.chainSelector);
         }
 
-        if (data.messageGas > selectorToChains[data.chainSelector].messageGasLimit) {
+        if (chain.targetTeller == address(0)) {
+            revert MultiChainTellerBase_TargetTellerIsZeroAddress();
+        }
+
+        if (data.destinationChainReceiver == address(0)) {
+            revert MultiChainTellerBase_DestinationChainReceiverIsZeroAddress();
+        }
+
+        if (data.messageGas > chain.messageGasLimit) {
             revert MultiChainTellerBase_GasLimitExceeded();
         }
 
-        if (data.messageGas < selectorToChains[data.chainSelector].minimumMessageGas) {
+        if (data.messageGas < chain.minimumMessageGas) {
             revert MultiChainTellerBase_GasTooLow();
         }
     }