From bdb38c4730f699ae1731533c3293af28e29b5e66 Mon Sep 17 00:00:00 2001
From: fufesou <linlong1266@gmail.com>
Date: Tue, 14 Jul 2026 15:35:52 +0800
Subject: [PATCH] fix: check valid id (#15535)

Signed-off-by: fufesou <linlong1266@gmail.com>
---
 src/common.rs           | 37 +++++++++++++++++++++++++++++++++++++
 src/lan.rs              |  8 ++++++++
 src/platform/windows.rs |  4 ++++
 3 files changed, 49 insertions(+)

diff --git a/src/common.rs b/src/common.rs
index b875d548c..76aac3874 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -2623,6 +2623,20 @@ pub fn is_direct_ip_access(peer: &str) -> bool {
     hbb_common::is_ip_str(peer) || hbb_common::is_domain_port_str(peer)
 }
 
+// Align the maximum length of the peer id to the maximum length of the peer id in the server.
+const MAX_UNTRUSTED_PEER_ID_LEN: usize = 253;
+const UNTRUSTED_PEER_ID_FORBIDDEN_CHARS: &[char] = &['"', '<', '>', '/', '\\', '|', '?', '*'];
+
+// Shared validation for peer/connect ids that cross untrusted boundaries before
+// they are stored or written into command/script contexts.
+pub fn is_valid_untrusted_peer_id(id: &str) -> bool {
+    !id.is_empty()
+        && id.len() <= MAX_UNTRUSTED_PEER_ID_LEN
+        && !id.chars().any(|ch| {
+            ch.is_control() || ch.is_whitespace() || UNTRUSTED_PEER_ID_FORBIDDEN_CHARS.contains(&ch)
+        })
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -2653,6 +2667,29 @@ mod tests {
         )
     }
 
+    #[test]
+    fn untrusted_peer_id_validation() {
+        let cases = [
+            ("123456789", true),
+            ("m\u{00FC}nchen-pc", true),
+            ("192.168.1.10:21118", true),
+            ("9123456234@public", true),
+            (
+                r#"1" & oWS.Run("cmd.exe /k whoami /priv",1,False) & ""#,
+                false,
+            ),
+            ("", false),
+            ("peer id", false),
+            ("peer\nid", false),
+            ("peer/id", false),
+            ("peer?id", false),
+        ];
+
+        for (id, expected) in cases {
+            assert_eq!(is_valid_untrusted_peer_id(id), expected, "{id:?}");
+        }
+    }
+
     // ThrottledInterval tick at the same time as tokio interval, if no sleeps
     #[allow(non_snake_case)]
     #[tokio::test]
diff --git a/src/lan.rs b/src/lan.rs
index 38c31adf9..2a648aab0 100644
--- a/src/lan.rs
+++ b/src/lan.rs
@@ -241,6 +241,14 @@ fn wait_response(
                     Some(rendezvous_message::Union::PeerDiscovery(p)) => {
                         last_recv_time = Instant::now();
                         if p.cmd == "pong" {
+                            if !crate::common::is_valid_untrusted_peer_id(&p.id) {
+                                log::warn!(
+                                    "Ignoring LAN discovery response from {} with invalid peer id",
+                                    addr
+                                );
+                                continue;
+                            }
+
                             let local_mac = if try_get_ip_by_peer {
                                 if let Some(self_addr) = get_ipaddr_by_peer(&addr) {
                                     get_mac(&self_addr)
diff --git a/src/platform/windows.rs b/src/platform/windows.rs
index b6b5b39d9..161365cdc 100644
--- a/src/platform/windows.rs
+++ b/src/platform/windows.rs
@@ -2278,6 +2278,10 @@ fn get_shortcut_icon_location(install_dir: &str, exe: &str) -> String {
 }
 
 pub fn create_shortcut(id: &str) -> ResultType<()> {
+    if !crate::common::is_valid_untrusted_peer_id(id) {
+        bail!("Invalid peer id for shortcut");
+    }
+
     let exe = std::env::current_exe()?.to_str().unwrap_or("").to_owned();
     // https://github.com/rustdesk/rustdesk/issues/13735
     // Replace ':' with '_' for filename since ':' is not allowed in Windows filenames