From 3a223ca3ebc7ac24d7726a0cd58e5695bc813657 Mon Sep 17 00:00:00 2001
From: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Date: Sat, 13 Jan 2018 21:00:47 +0100
Subject: [PATCH] CVE-2018-5704: Prevent some forms of Cross Protocol Scripting
attacks
OpenOCD can be targeted by a Cross Protocol Scripting attack from
a web browser running malicious code, such as the following PoC:
var x = new XMLHttpRequest();
x.open("POST", "http://127.0.0.1:4444", true);
x.send("exec xcalc\r\n");
This mitigation should provide some protection from browser-based
attacks and is based on the corresponding fix in Redis:
https://github.com/antirez/redis/blob/8075572207b5aebb1385c4f233f5302544439325/src/networking.c#L1758
Change-Id: Ia96ebe19b74b5805dc228bf7364c7971a90a4581
Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Reported-by: Josef Gajdusek <atx@atx.name>
---
src/server/startup.tcl | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/src/server/startup.tcl b/src/server/startup.tcl
index 64ace4079..dd1b31e41 100644
--- a/src/server/startup.tcl
+++ b/src/server/startup.tcl
@@ -8,3 +8,14 @@ proc ocd_gdb_restart {target_id} {
# one target
reset halt
}
+
+proc prevent_cps {} {
+ echo "Possible SECURITY ATTACK detected."
+ echo "It looks like somebody is sending POST or Host: commands to OpenOCD."
+ echo "This is likely due to an attacker attempting to use Cross Protocol Scripting"
+ echo "to compromise your OpenOCD instance. Connection aborted."
+ exit
+}
+
+proc POST {args} { prevent_cps }
+proc Host: {args} { prevent_cps }
--
2.20.1