openocd: add security fix for CVE-2018-5704

Open On-Chip Debugger (OpenOCD) 0.10.0 does not block attempts to use HTTP
POST for sending data to 127.0.0.1 port 4444, which allows remote attackers
to conduct cross-protocol scripting attacks, and consequently execute
arbitrary commands, via a crafted web site.

For more details, see:
https://sourceforge.net/p/openocd/mailman/message/36188041/

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

diff --git a/package/openocd/0003-CVE-2018-5704-Prevent-some-forms-of-Cross-Protocol-S.patch b/package/openocd/0003-CVE-2018-5704-Prevent-some-forms-of-Cross-Protocol-S.patch
new file mode 100644 (file)
index 0000000..ba19bf5
--- /dev/null
+++ b/package/openocd/0003-CVE-2018-5704-Prevent-some-forms-of-Cross-Protocol-S.patch
@@ -0,0 +1,50 @@
+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
+
+
+Upstream-status: Under review: http://openocd.zylin.com/#/c/4335/
+Change-Id: Ia96ebe19b74b5805dc228bf7364c7971a90a4581
+Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
+Reported-by: Josef Gajdusek <atx@atx.name>
+Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
+---
+ src/server/startup.tcl | 11 +++++++++++
+ 1 file changed, 11 insertions(+)
+
+diff --git a/src/server/startup.tcl b/src/server/startup.tcl
+index 64ace407..dd1b31e4 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 }
+-- 
+2.11.0
+