[13210] in bugtraq

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Re: majordomo local exploit

daemon@ATHENA.MIT.EDU (Dale Clark)
Tue Jan 4 17:12:28 2000

Mime-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Message-Id:  <1000103163835.ZM243070@coleen.arsc.edu>
Date:         Mon, 3 Jan 2000 16:38:35 +0000
Reply-To: Dale Clark <clark@ARSC.EDU>
From: Dale Clark <clark@ARSC.EDU>
X-To:         BUGTRAQ@SECURITYFOCUS.COM
To: BUGTRAQ@SECURITYFOCUS.COM

  The following patch, built upon code and suggestions submitted by
Henrik Edlund, Henrik Nordstrom, and Andrew Brown, is intended to render
safe the config file requires, in the seven scripts which use them, in
the Majordomo 1.94.4 home directory. It also incorporates Todd Miller's
patch of Dec. 29.
  Basically, it replaces each "require $cf" with the following:

if (not sysopen CONFIG,$cf,O_RDONLY)
{
  die sprintf qq|Unable to sysopen config file "$cf"%s.\n|,$! ? ": $!" : '';
}
elsif ((stat CONFIG)[4] != $>)
{
  die qq|Config file "$cf" not owned by effective UID.\n|;
}
elsif (eval(join '',<CONFIG>),$@)
{
  die qq|Unable to eval "$cf": $@.\n|;
}
else
{
  close CONFIG;
}

  Use by cd'ing to Majordomo HOME, and issuing
"patch < majorodomo-1.94.4.patch". Be sure to "chmod a-x *orig" after.

Dale V. Clark                                             clark@arsc.edu
Systems Analyst                                             907-474-5114
Arctic Region Supercomputing Center                         www.arsc.edu

======================== majordomo-1.94.4.patch ========================
--- archive2.pl	Mon Jan  3 14:35:32 2000
+++ archive2.pl.new	Mon Jan  3 14:36:16 2000
@@ -54,10 +54,23 @@
     shift(@ARGV);
     shift(@ARGV);
 }
-if (! -r $cf) {
-    die("$cf not readable; stopped");
+
+if (not sysopen CONFIG,$cf,O_RDONLY)
+{
+  die sprintf qq|Unable to sysopen config file "$cf"%s.\n|,$! ? ": $!" : '';
 }
-require "$cf";
+elsif ((stat CONFIG)[4] != $>)
+{
+  die qq|Config file "$cf" not owned by effective UID.\n|;
+}
+elsif (eval(join '',<CONFIG>),$@)
+{
+  die qq|Unable to eval "$cf": $@.\n|;
+}
+else
+{
+  close CONFIG;
+}

 # All these should be in the standard PERL library
 unshift(@INC, $homedir);
--- bounce-remind	Mon Jan  3 14:35:32 2000
+++ bounce-remind.new	Mon Jan  3 14:38:16 2000
@@ -24,10 +24,23 @@
     shift(@ARGV);
     shift(@ARGV);
 }
-if (! -r $cf) {
-    die("$cf not readable; stopped");
+
+if (not sysopen CONFIG,$cf,O_RDONLY)
+{
+  die sprintf qq|Unable to sysopen config file "$cf"%s.\n|,$! ? ": $!" : '';
 }
-require "$cf";
+elsif ((stat CONFIG)[4] != $>)
+{
+  die qq|Config file "$cf" not owned by effective UID.\n|;
+}
+elsif (eval(join '',<CONFIG>),$@)
+{
+  die qq|Unable to eval "$cf": $@.\n|;
+}
+else
+{
+  close CONFIG;
+}

 # Go to the home directory specified by the .cf file
 chdir("$homedir");
--- config-test	Mon Jan  3 14:35:32 2000
+++ config-test.new	Mon Jan  3 14:58:05 2000
@@ -119,10 +119,21 @@

 $cf = $ARGV[0] || $ENV{'MAJORDOMO_CF'};

-if (eval "require '$cf'") {
-    &good("'require'd $cf okay.");
-} else {
-    &bad("something's wrong with $cf: $@");
+if (not sysopen CONFIG,$cf,O_RDONLY)
+{
+  die sprintf qq|Unable to sysopen config file "$cf"%s.\n|,$! ? ": $!" : '';
+}
+elsif ((stat CONFIG)[4] != $>)
+{
+  die qq|Config file "$cf" not owned by effective UID.\n|;
+}
+elsif (eval(join '',<CONFIG>),$@)
+{
+  die qq|Unable to eval "$cf": $@.\n|;
+}
+else
+{
+  close CONFIG;
 }

 foreach (@requires) {
--- digest	Mon Jan  3 14:35:32 2000
+++ digest.new	Mon Jan  3 15:07:34 2000
@@ -315,7 +315,23 @@
 		# Read and execute the .cf file
 		$cf = $opt_c || $ENV{"MAJORDOMO_CF"} ||
 		    "/etc/majordomo.cf";
-		require "$cf";
+
+if (not sysopen CONFIG,$cf,O_RDONLY)
+{
+  die sprintf qq|Unable to sysopen config file "$cf"%s.\n|,$! ? ": $!" : '';
+}
+elsif ((stat CONFIG)[4] != $>)
+{
+  die qq|Config file "$cf" not owned by effective UID.\n|;
+}
+elsif (eval(join '',<CONFIG>),$@)
+{
+  die qq|Unable to eval "$cf": $@.\n|;
+}
+else
+{
+  close CONFIG;
+}

 		chdir($homedir);

--- majordomo	Mon Jan  3 13:37:13 2000
+++ majordomo.new	Mon Jan  3 14:15:29 2000
@@ -40,11 +40,23 @@
 	die "Unknown argument $ARGV[0]\n";
     }
 }
-if (! -r $cf) {
-    die("$cf not readable; stopped");
-}

-require "$cf";
+if (not sysopen CONFIG,$cf,O_RDONLY)
+{
+  die sprintf qq|Unable to sysopen config file "$cf"%s.\n|,$! ? ": $!" : '';
+}
+elsif ((stat CONFIG)[4] != $>)
+{
+  die qq|Config file "$cf" not owned by effective UID.\n|;
+}
+elsif (eval(join '',<CONFIG>),$@)
+{
+  die qq|Unable to eval "$cf": $@.\n|;
+}
+else
+{
+  close CONFIG;
+}

 # Go to the home directory specified by the .cf file
 chdir("$homedir") || die "chdir to $homedir failed, $!\n";
--- request-answer	Mon Jan  3 14:35:32 2000
+++ request-answer.new	Mon Jan  3 15:09:02 2000
@@ -20,10 +20,23 @@
     shift(@ARGV);
     shift(@ARGV);
 }
-if (! -r $cf) {
-    die("$cf not readable; stopped");
+
+if (not sysopen CONFIG,$cf,O_RDONLY)
+{
+  die sprintf qq|Unable to sysopen config file "$cf"%s.\n|,$! ? ": $!" : '';
 }
-require "$cf";
+elsif ((stat CONFIG)[4] != $>)
+{
+  die qq|Config file "$cf" not owned by effective UID.\n|;
+}
+elsif (eval(join '',<CONFIG>),$@)
+{
+  die qq|Unable to eval "$cf": $@.\n|;
+}
+else
+{
+  close CONFIG;
+}

 chdir($homedir) || die("Can't chdir(\"$homedir\"): $!");
 unshift(@INC, $homedir);
--- resend	Mon Jan  3 15:14:49 2000
+++ resend.new	Mon Jan  3 15:16:01 2000
@@ -56,7 +56,7 @@
 if ($ARGV[0] =~ /^\@/) {
     $fn = shift(@ARGV);
     $fn =~ s/^@//;
-    open(AV, $fn) || die("open(AV, \"$fn\"): $!\nStopped");
+    sysopen(AV, $fn, O_RDONLY) || die("sysopen(AV, \"$fn\", O_RDONLY):
$!\nStopped");
     undef($/);	# set input field separator
     $av = <AV>;	# read whole file into string
     close(AV);
@@ -84,11 +84,23 @@
 # Despite not having a place to send the remains of the body,
 # it would be nice to send a message to root or postmaster, at least...
 #
-if (! -r $cf) {
-    die("$cf not readable; stopped");
-}

-require "$cf";
+if (not sysopen CONFIG,$cf,O_RDONLY)
+{
+  die sprintf qq|Unable to sysopen config file "$cf"%s.\n|,$! ? ": $!" : '';
+}
+elsif ((stat CONFIG)[4] != $>)
+{
+  die qq|Config file "$cf" not owned by effective UID.\n|;
+}
+elsif (eval(join '',<CONFIG>),$@)
+{
+  die qq|Unable to eval "$cf": $@.\n|;
+}
+else
+{
+  close CONFIG;
+}

 chdir($homedir) || die("Can't chdir(\"$homedir\"): $!");

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