From 0a45f5e71a1f55740c40e2a1be5e5426788300ed Mon Sep 17 00:00:00 2001
From: teidesu <me@tei.su>
Date: Tue, 15 Jun 2021 03:11:52 +0300
Subject: [PATCH] fix(core): check for correct padding

---
 packages/core/src/network/mtproto-session.ts | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/packages/core/src/network/mtproto-session.ts b/packages/core/src/network/mtproto-session.ts
index 3d0b0e14..3878db23 100644
--- a/packages/core/src/network/mtproto-session.ts
+++ b/packages/core/src/network/mtproto-session.ts
@@ -187,6 +187,17 @@ export class MtprotoSession {
         }
 
         const content = innerReader.object()
+
+        const paddingSize = innerData.length - innerReader.pos
+
+        if (paddingSize < 12 || paddingSize > 1024) {
+            debug(
+                'warn: ignoring message with invalid padding size: %d',
+                paddingSize
+            )
+            return null
+        }
+
         return {
             messageId,
             seqNo,