Security: Prevent integer overflow conversion to uint64

internal/pop3/server.go

@@ -215,7 +215,7 @@ func handleTransactionCommand(conn net.Conn, cmd string, args []string, messages
 		for _, m := range messages {
 			totalSize += m.Size
 		}
-		sendResponse(conn, fmt.Sprintf("+OK %d %d", len(messages), int64(totalSize)))
+		sendResponse(conn, fmt.Sprintf("+OK %d %d", len(messages), totalSize))
 	case "LIST":
 		totalSize := uint64(0)
 		for _, m := range messages {
@@ -229,12 +229,12 @@ func handleTransactionCommand(conn net.Conn, cmd string, args []string, messages
 				sendResponse(conn, "-ERR no such message")
 				return
 			}
-			sendResponse(conn, fmt.Sprintf("+OK %d %d", nr, int64(messages[nr-1].Size)))
+			sendResponse(conn, fmt.Sprintf("+OK %d %d", nr, messages[nr-1].Size))
 		} else {
-			sendResponse(conn, fmt.Sprintf("+OK %d messages (%d octets)", len(messages), int64(totalSize)))
+			sendResponse(conn, fmt.Sprintf("+OK %d messages (%d octets)", len(messages), totalSize))
 
 			for row, m := range messages {
-				sendResponse(conn, fmt.Sprintf("%d %d", row+1, int64(m.Size))) // Convert Size to int64 when printing
+				sendResponse(conn, fmt.Sprintf("%d %d", row+1, m.Size))
 			}
 			sendResponse(conn, ".")
 		}

internal/stats/stats.go

@@ -9,6 +9,7 @@ import (
 	"github.com/axllent/mailpit/config"
 	"github.com/axllent/mailpit/internal/logger"
 	"github.com/axllent/mailpit/internal/storage"
+	"github.com/axllent/mailpit/internal/tools"
 )
 
 // Stores cached version  along with its expiry time and error count.
@@ -146,7 +147,7 @@ func Track() {
 func LogSMTPAccepted(size int) {
 	mu.Lock()
 	smtpAccepted = smtpAccepted + 1
-	smtpAcceptedSize = smtpAcceptedSize + uint64(size)
+	smtpAcceptedSize = smtpAcceptedSize + tools.SafeUint64(size)
 	mu.Unlock()
 }
 

internal/storage/messages.go

@@ -108,7 +108,7 @@ func Store(body *[]byte, username *string) (string, error) {
 
 	if config.Compression > 0 {
 		// insert compressed raw message
-		compressed := dbEncoder.EncodeAll(*body, make([]byte, 0, int(size)))
+		compressed := dbEncoder.EncodeAll(*body, make([]byte, 0, size))
 
 		if sqlDriver == "rqlite" {
 			// rqlite does not support binary data in query, so we need to encode the compressed message into hexadecimal
@@ -202,7 +202,7 @@ func Store(body *[]byte, username *string) (string, error) {
 
 	BroadcastMailboxStats()
 
-	logger.Log().Debugf("[db] saved message %s (%d bytes)", id, int64(size))
+	logger.Log().Debugf("[db] saved message %s (%d bytes)", id, size)
 
 	return id, nil
 }

internal/storage/utils.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/axllent/mailpit/internal/html2text"
 	"github.com/axllent/mailpit/internal/logger"
+	"github.com/axllent/mailpit/internal/tools"
 	"github.com/jhillyerd/enmime/v2"
 )
 
@@ -88,7 +89,7 @@ func cleanString(str string) string {
 // LogMessagesDeleted logs the number of messages deleted
 func logMessagesDeleted(n int) {
 	mu.Lock()
-	StatsDeleted = StatsDeleted + uint64(n)
+	StatsDeleted = StatsDeleted + tools.SafeUint64(n)
 	mu.Unlock()
 }
 

internal/tools/utils.go

@@ -36,3 +36,22 @@ func Normalize(s string) string {
 
 	return strings.TrimSpace(s)
 }
+
+// SafeUint64 converts an int or int64 to uint64, ensuring it does not exceed the maximum value for uint64.
+func SafeUint64(i any) uint64 {
+	switch v := i.(type) {
+	case int:
+		if v < 0 {
+			return 0
+		}
+		return uint64(v)
+	case int64:
+		if v < 0 {
+			return 0
+		}
+		return uint64(v)
+	default:
+		// only accepts int or int64
+		return 0
+	}
+}

server/apiv1/messages.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"github.com/axllent/mailpit/internal/storage"
+	"github.com/axllent/mailpit/internal/tools"
 )
 
 // MessagesSummary is a summary of a list of messages
@@ -241,9 +242,9 @@ func Search(w http.ResponseWriter, r *http.Request) {
 
 	res.Start = start
 	res.Messages = messages
-	res.Count = uint64(len(messages)) // legacy - now undocumented in API specs
-	res.Total = stats.Total           // total messages in mailbox
-	res.MessagesCount = uint64(results)
+	res.Count = tools.SafeUint64(len(messages)) // legacy - now undocumented in API specs
+	res.Total = stats.Total                     // total messages in mailbox
+	res.MessagesCount = tools.SafeUint64(results)
 	res.Unread = stats.Unread
 	res.Tags = stats.Tags
 
@@ -253,7 +254,7 @@ func Search(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	res.MessagesUnreadCount = uint64(unread)
+	res.MessagesUnreadCount = tools.SafeUint64(unread)
 
 	w.Header().Add("Content-Type", "application/json")
 	if err := json.NewEncoder(w).Encode(res); err != nil {