From 2f1d8c5e662d66967c57474dd5f6609d9377831e Mon Sep 17 00:00:00 2001 From: David Cook Date: Thu, 4 Sep 2025 01:20:38 +0000 Subject: [PATCH] Bug 40748: Check for HTTP URLs and skip shell when using system() This change checks for HTTP(S) URLs and skips the shell when using system() so that shell metacharacters aren't interpreted. Test plan: 0. Apply the patch 1. Insert the following into the Babeltheque_url_update system preference: $(whoami > /tmp/rce.log) 2. koha-shell kohadev 3. perl misc/cronjobs/social_data/update_social_data.pl 4. Note the script says the following: $(whoami > /tmp/rce.log) is not a HTTP URL. Aborting. 5. Note also that /tmp/rce.log is not created 6. Change Babeltheque_url_update syspref to something like the following: http://localhost:8080 7. perl misc/cronjobs/social_data/update_social_data.pl 8. Note that the wget succeeds but the bunzip2 fails (as expected) since we haven't fetched a bzipped file 9. Try to create a payload that passes the HTTP URL test with shell metacharacters and note that they're not interpetted and instead just used as part of a URL string. --- .../social_data/update_social_data.pl | 25 +++++++++++++------ 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/misc/cronjobs/social_data/update_social_data.pl b/misc/cronjobs/social_data/update_social_data.pl index dff5a1c485..bee3f8090e 100755 --- a/misc/cronjobs/social_data/update_social_data.pl +++ b/misc/cronjobs/social_data/update_social_data.pl @@ -5,13 +5,22 @@ use Modern::Perl; use Koha::Script -cron; use C4::Context; use C4::SocialData; +use URI; -my $url = quotemeta( C4::Context->preference("Babeltheque_url_update") ); -my $output_dir = qq{/tmp}; -my $output_filepath = qq{$output_dir/social_data.csv}; -system(qq{/bin/rm -f $output_filepath}); -system(qq{/bin/rm -f $output_dir/social_data.csv.bz2}); -system(qq{/usr/bin/wget $url -O $output_dir/social_data.csv.bz2 }) == 0 or die "Can't get bz2 file from url $url ($?)"; -system(qq{/bin/bunzip2 $output_dir/social_data.csv.bz2 }) == 0 or die "Can't extract bz2 file ($?)"; +my $syspref_value = C4::Context->preference("Babeltheque_url_update"); +my $url = URI->new($syspref_value); -C4::SocialData::update_data $output_filepath; +#NOTE: Both HTTP and HTTPS URLs are instances of the URI::http class +if ( $url && ref $url && $url->isa('URI::http') ) { + my $output_dir = qq{/tmp}; + my $output_filepath = qq{$output_dir/social_data.csv}; + system(qq{/bin/rm -f $output_filepath}); + system(qq{/bin/rm -f $output_dir/social_data.csv.bz2}); + system( '/usr/bin/wget', $url, '-O', "$output_dir/social_data.csv.bz2" ) == 0 + or die "Can't get bz2 file from url $url ($?)"; + system(qq{/bin/bunzip2 $output_dir/social_data.csv.bz2 }) == 0 or die "Can't extract bz2 file ($?)"; + + C4::SocialData::update_data $output_filepath; +} else { + print "$syspref_value is not a HTTP URL. Aborting.\n"; +} -- 2.39.5