rest: Reject negative outpoint index in getutxos parsing

2 files changed, 8 insertions, 4 deletions

diff --git a/src/rest.cpp b/src/rest.cpp
index 4abbc4d2ca..185508d2c9 100644
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -788,14 +788,15 @@ static bool rest_getutxos(const std::any& context, HTTPRequest* req, const std::
 
         for (size_t i = (fCheckMemPool) ? 1 : 0; i < uriParts.size(); i++)
         {
-            int32_t nOutput;
             std::string strTxid = uriParts[i].substr(0, uriParts[i].find('-'));
             std::string strOutput = uriParts[i].substr(uriParts[i].find('-')+1);
+            auto output{ToIntegral<uint32_t>(strOutput)};
 
-            if (!ParseInt32(strOutput, &nOutput) || !IsHex(strTxid))
+            if (!output || !IsHex(strTxid)) {
                 return RESTERR(req, HTTP_BAD_REQUEST, "Parse error");
+            }
 
-            vOutPoints.emplace_back(TxidFromString(strTxid), (uint32_t)nOutput);
+            vOutPoints.emplace_back(TxidFromString(strTxid), *output);
         }
 
         if (vOutPoints.size() > 0)
diff --git a/test/functional/interface_rest.py b/test/functional/interface_rest.py
index ae8d6b226d..aa201cb85b 100755
--- a/test/functional/interface_rest.py
+++ b/test/functional/interface_rest.py
@@ -201,10 +201,13 @@ class RESTTest (BitcoinTestFramework):
         json_obj = self.test_rest_request(f"/getutxos/checkmempool/{spending[0]}-{spending[1]}")
         assert_equal(len(json_obj['utxos']), 1)
 
-        # Do some invalid requests
+        self.log.info("Check some invalid requests")
         self.test_rest_request("/getutxos", http_method='POST', req_type=ReqType.JSON, body='{"checkmempool', status=400, ret_type=RetType.OBJ)
         self.test_rest_request("/getutxos", http_method='POST', req_type=ReqType.BIN, body='{"checkmempool', status=400, ret_type=RetType.OBJ)
         self.test_rest_request("/getutxos/checkmempool", http_method='POST', req_type=ReqType.JSON, status=400, ret_type=RetType.OBJ)
+        self.test_rest_request(f"/getutxos/{spending[0]}_+1", ret_type=RetType.OBJ, status=400)
+        self.test_rest_request(f"/getutxos/{spending[0]}-+1", ret_type=RetType.OBJ, status=400)
+        self.test_rest_request(f"/getutxos/{spending[0]}--1", ret_type=RetType.OBJ, status=400)
 
         # Test limits
         long_uri = '/'.join([f"{txid}-{n_}" for n_ in range(20)])