From 0c1ec098795b4d7b2405b59ec238f90611f6b78d Mon Sep 17 00:00:00 2001
From: Philippe Antoine <pantoine@oisf.net>
Date: Wed, 22 Jul 2026 18:31:53 +0200
Subject: [PATCH] enip: avoid quadratic complexity with multiple service packet

Ticket: 8757
---
 rust/src/enip/parser.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/rust/src/enip/parser.rs b/rust/src/enip/parser.rs
index 668e14fed4..f171c65642 100644
--- a/rust/src/enip/parser.rs
+++ b/rust/src/enip/parser.rs
@@ -235,6 +235,12 @@ pub fn parse_cip_reqresp_multiple(
     let mut size_list = Vec::new();
     let mut rem = i;
     for j in 0..nb as usize {
+        // require offsets list to be strictly increasing
+        // Avoid having multiple times the same offset,
+        // and reparsing the same expensive structure quadratically
+        if (offset_list[j] as usize) < start.len() - rem.len() {
+            return Err(nom8::Err::Error(make_error(i, ErrorKind::Satisfy)));
+        }
         if (offset_list[j] as usize) < start.len() {
             let (rem2, packet) = parse_cip_multi(&start[offset_list[j] as usize..])?;
             packet_list.push(packet);