[UNIX] mysqlhotcopy Insecure Temporary File (copy_index)

• Previous message: SecuriTeam: "[NT] IPD Local System Denial of Service"
• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] [ attachment ]

To: list@securiteam.com
Date: 18 Aug 2004 14:23:51 +0200

The following security advisory is sent to the securiteam mailing list, and can be found at the SecuriTeam web site: http://www.securiteam.com
- - promotion

The SecuriTeam alerts list - Free, Accurate, Independent.

Get your security news from a reliable source.
http://www.securiteam.com/mailinglist.html

- - - - - - - - -

  mysqlhotcopy Insecure Temporary File (copy_index)
------------------------------------------------------------------------

SUMMARY

mysqlhotcopy is "a fast on-line hot-backup utility for local MySQL
databases and tables".

A vulnerability in mysqlhotcopy allows local attackers to cause the
product to overwrite create a symbolic link in the /tmp/ directory that
will be then overwritten by the mysqlhotcopy utility.

DETAILS

Insecure temporary file vulnerability in the mysqlhotcopy script has been
discovered. This insecure temporary file occurs when using the scp (Secure
CoPy) method that is part of the mysql-server package. Creating a
temporary file whose name is predictable enough to allow overwriting of
arbitrary files causes the vulnerability.

Vulnerable code:
Under the function copy_index, the following code can be seen:
  my $tmpfile="$opt_tmpdir/mysqlhotcopy$$";

This file is then written to by the script.

Patch:
The following is Debian's mysqlhotcopy provided patch:
--- mysql-3.23.49.orig/scripts/mysqlhotcopy.sh
+++ mysql-3.23.49/scripts/mysqlhotcopy.sh
@@ -7,6 +7,8 @@
 use File::Path;
 use DBI;
 use Sys::Hostname;
+use File::Copy;
+use File::Temp;

 =head1 NAME

@@ -585,7 +587,6 @@
 sub copy_index
 {
   my ($method, $files, $source, $target) = @_;
- my $tmpfile="$opt_tmpdir/mysqlhotcopy$$";

   print "Copying indices for ".@$files." files...\n" unless $opt{quiet};
   foreach my $file (@$files)
@@ -613,21 +614,21 @@
     }
     elsif ($opt{method} eq 'scp')
     {
- my $tmp=$tmpfile;
- open(OUTPUT,">$tmp") || die "Can\'t create file $tmp: $!\n";
- if (syswrite(OUTPUT,$buff) != length($buff))
+ my ($fh, $tmp)=tempfile('mysqlhotcopy-XXXXXX', DIR => $opt_tmpdir);
+ die "Can\'t create/open file in $opt_tmpdir\n";
+ if (syswrite($fh,$buff) != length($buff))
       {
  die "Error when writing data to $tmp: $!\n";
       }
- close OUTPUT || die "Error on close of $tmp: $!\n";
- safe_system("scp $tmp $to");
+ close $fh || die "Error on close of $tmp: $!\n";
+ safe_system("$opt{method} $tmp $to");
+ unlink $tmp;
     }
     else
     { die "Can't use unsupported method '$opt{method}'\n";
     }
   }
- unlink "$tmpfile" if ($opt{method} eq 'scp');
 }

ADDITIONAL INFORMATION

The information has been provided by <mailto:jeroen@wolffelaar.nl> Jeroen
van Wolffelaar.

========================================

This bulletin is sent to members of the SecuriTeam mailing list.
To unsubscribe from the list, send mail with an empty subject line and body to: list-unsubscribe@securiteam.com
In order to subscribe to the mailing list, simply forward this email to: list-subscribe@securiteam.com

====================
====================

DISCLAIMER:
The information in this bulletin is provided "AS IS" without warranty of any kind.
In no event shall we be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages.

• Previous message: SecuriTeam: "[NT] IPD Local System Denial of Service"
• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] [ attachment ]