From ae65651eab053fc6dc4590dbb863a268215c1fc5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= Date: Fri, 8 Jun 2018 11:45:40 +0100 Subject: [PATCH] [PATCH] Remove existing files before overwriting them Archive should extract only the latest same-named entry. Extracted regular file should not be writtent into existing block device (or any other one). https://rt.cpan.org/Ticket/Display.html?id=125523 Signed-off-by: Chris 'BinGOs' Williams --- lib/Archive/Tar.pm | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/lib/Archive/Tar.pm b/lib/Archive/Tar.pm index 6244369..a83975f 100644 --- a/lib/Archive/Tar.pm +++ b/lib/Archive/Tar.pm @@ -842,6 +842,20 @@ sub _extract_file { return; } + ### If a file system already contains a block device with the same name as + ### the being extracted regular file, we would write the file's content + ### to the block device. So remove the existing file (block device) now. + ### If an archive contains multiple same-named entries, the last one + ### should replace the previous ones. So remove the old file now. + ### If the old entry is a symlink to a file outside of the CWD, the new + ### entry would create a file there. This is CVE-2018-12015 + ### . + if (-l $full || -e _) { + if (!unlink $full) { + $self->_error( qq[Could not remove old file '$full': $!] ); + return; + } + } if( length $entry->type && $entry->is_file ) { my $fh = IO::File->new; $fh->open( '>' . $full ) or (