From 84d67a239bfe064d0fb1a6c4167b3262b9ae08b8 Mon Sep 17 00:00:00 2001
From: DayShift <113507098+ShiyuBanzhou@users.noreply.github.com>
Date: Sun, 26 Jan 2025 01:15:39 +0800
Subject: [PATCH] Update server/notification-providers/pushdeer.js

More concise and reasonable regular expression fix

Co-authored-by: Frank Elsinga <frank@elsinga.de>
---
 server/notification-providers/pushdeer.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/server/notification-providers/pushdeer.js b/server/notification-providers/pushdeer.js
index 428f44703..e39d61d61 100644
--- a/server/notification-providers/pushdeer.js
+++ b/server/notification-providers/pushdeer.js
@@ -11,7 +11,8 @@ class PushDeer extends NotificationProvider {
     async send(notification, msg, monitorJSON = null, heartbeatJSON = null) {
         const okMsg = "Sent Successfully.";
         const serverUrl = notification.pushdeerServer || "https://api2.pushdeer.com";
-        const url = `${serverUrl.trim().replace(/(?<!\/)\/*$/, "")}/message/push`;
+        // capture group below is nessesary to prevent an ReDOS-attack
+        const url = `${serverUrl.trim().replace(/([^\/])\/+$/, "$1")}/message/push`;
 
         let valid = msg != null && monitorJSON != null && heartbeatJSON != null;