From 611881af105dbbcecbf6511cbf733a7f59d37fa9 Mon Sep 17 00:00:00 2001
From: Aurora Gaffney <aurora@blinklabs.io>
Date: Fri, 29 Aug 2025 14:35:16 -0400
Subject: [PATCH] refactor: return error when muxer receives zero-byte payload

Fixes #1018

Signed-off-by: Aurora Gaffney <aurora@blinklabs.io>
---
 muxer/muxer.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/muxer/muxer.go b/muxer/muxer.go
index ea384770..ad958d59 100644
--- a/muxer/muxer.go
+++ b/muxer/muxer.go
@@ -313,6 +313,14 @@ func (m *Muxer) readLoop() {
 			}
 			return
 		}
+		// Check for zero-byte payload
+		// This prevents certain types of DoS attacks
+		if header.PayloadLength == 0 {
+			m.sendError(
+				errors.New("received zero-byte segment payload"),
+			)
+			return
+		}
 		msg := &Segment{
 			SegmentHeader: header,
 			Payload:       make([]byte, header.PayloadLength),