From 4b7909221a399b218d7cc36d80ecf8fe53887ffe Mon Sep 17 00:00:00 2001 From: Jake Deery Date: Wed, 3 Sep 2025 15:41:14 +0000 Subject: [PATCH] Bug 40748: [24.05.x] Fix RCE in update_social_data.pl This patch fixes an identified RCE in the update_social_data.pl social_data, which when executed, allows an attacker to run arbitrary code on the system's shell. TO TEST: a) In the Babeltheque_url_update syspref, wrap any bash in $(), and then run the update_social_data.pl script. *) For example, $(whoami > /tmp/rce.log) will output to a file the username the perl script is running as. APPLY PATCH b) Run the update_social_data.pl script again. The string is now meta-escaped, and the RCE no longer works. Signed-off-by: Jonathan Druart 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. Signed-off-by: Jake Deery Signed-off-by: Jonathan Druart --- .../social_data/update_social_data.pl | 24 ++++++++++++------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/misc/cronjobs/social_data/update_social_data.pl b/misc/cronjobs/social_data/update_social_data.pl index 58e3dc06969..bee3f8090e6 100755 --- a/misc/cronjobs/social_data/update_social_data.pl +++ b/misc/cronjobs/social_data/update_social_data.pl @@ -5,14 +5,22 @@ use Modern::Perl; use Koha::Script -cron; use C4::Context; use C4::SocialData; +use URI; -my $url = 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); +#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; + C4::SocialData::update_data $output_filepath; +} else { + print "$syspref_value is not a HTTP URL. Aborting.\n"; +} -- 2.39.5