From 86236bd3390209a68f867aa9e56a7543634d0089 Mon Sep 17 00:00:00 2001
From: Xin LI <delphij@FreeBSD.org>
Date: Sat, 25 Jul 2015 00:21:29 +0000
Subject: [PATCH] Document the fact that system(3) can easily be misused due to
 shell meta characters are honored.  While I'm there also mention posix_spawn
 in the SEE ALSO section.

MFC after:	2 weeks
---
 lib/libc/stdlib/system.3 | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/lib/libc/stdlib/system.3 b/lib/libc/stdlib/system.3
index 3cea71ec79a9..4fd61bcda233 100644
--- a/lib/libc/stdlib/system.3
+++ b/lib/libc/stdlib/system.3
@@ -32,7 +32,7 @@
 .\"     @(#)system.3	8.1 (Berkeley) 6/4/93
 .\" $FreeBSD$
 .\"
-.Dd June 4, 1993
+.Dd July 25, 2015
 .Dt SYSTEM 3
 .Os
 .Sh NAME
@@ -87,7 +87,8 @@ failed.
 .Xr execve 2 ,
 .Xr fork 2 ,
 .Xr waitpid 2 ,
-.Xr popen 3
+.Xr popen 3 ,
+.Xr posix_spawn 3
 .Sh STANDARDS
 The
 .Fn system
@@ -97,3 +98,14 @@ conforms to
 and is expected to be
 .St -p1003.2
 compatible.
+.Sh SECURITY CONSIDERATIONS
+The
+.Fn system
+function is easily misused in a manner that enables a malicious
+user to run arbitrary command,
+because all meta-characters supported by
+.Xr sh 1
+would be honored.
+User supplied parameters should always be carefully santized
+before they appear in
+.Fa string.