misc/169796: kenv(1) output is unreadable

[Arnaud Lacombe]

>Number:         169796
>Category:       misc
>Synopsis:       kenv(1) output is unreadable
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Jul 12 02:40:00 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     Arnaud Lacombe
>Release:        many.
>Organization:
n/a
>Environment:
FreeBSD coltar 9.0-STABLE FreeBSD 9.0-STABLE
>Description:
Output of kenv(1) is not escaped to be safely usable on terminals. Depending their content, variable value might end up being interpreted as terminal command. On 9.0-stable, we ends up having the following being output:

LINES="24"
ansi_caption[1]="ESC[1mBESC[37moot ESC[1m[ENTER]ESC[37m"
ansi_caption[2]="ESC[1mEscESC[37mape to loader prompt"
ansi_caption[4]="ESC[1mAESC[37mCPI Support: ESC[34;1mDisabledESC[37m"
ansi_caption[5]="Boot Safe ESC[1mMESC[37mode: ESC[34;1mNOESC[37m"
ansi_caption[6]="Boot ESC[1mSESC[37mingle User: ESC[34;1mNOESC[37m"
ansi_caption[7]="Boot ESC[1mVESC[37merbose: ESC[34;1mNOESC[37m"
bootfile="kernel"
comconsole_speed="115200"
console="comconsole"
currdev="disk0p2:"

Of course, ESC are not escaped and result in kenv(1)'s being unreadable.
>How-To-Repeat:
# kenv
>Fix:
escape variable content not to be interpreted as terminal command.

>Release-Note:
>Audit-Trail:
>Unformatted: