l i n u x - u s e r s - g r o u p - o f - d a v i s
Next Meeting:
March 16: Community Fiber Optic for Davis
Next Installfest:
Latest News:
Feb. 5: LUGOD seeking speakers for 2015
Page last updated:
2002 Feb 20 17:18

The following is an archive of a post made to our 'vox-tech mailing list' by one of its subscribers.

Report this post as spam:

(Enter your email address)
[vox-tech] Need help securing a simple perl CGI
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[vox-tech] Need help securing a simple perl CGI

Hash: SHA1

This is a perl cgi script I wrote to allow me to have large html files on my 
web host without exceeding my storage quota.

I'd like it looked at, _I_ can no longer abuse it to run random commands or 
go where I shouldn't, but that doesn't mean others can'.

Any other feedback would also be great.

#Let users transparently access files that are gzipped server-side
#Useful only to keep under my storage quota ;-)

my $in = $ENV{'QUERY_STRING'};		# Handle CGI calls
$in =~ s/\+/ /g;			# Replace '+' with ' '
$in =~ s/%(..)/pack("c",hex($1))/ge;	# Undo URL quoting

$in =~ s/\.\.//g;			# Foil Nasty h4x0rz trying to desend
					# directories
$in =~ s/\\//g;				# There is no need for backslashes!
$in =~ s/\'//g;				# prevent h4x0rz from
					# running commands like
					# zcat.cgi?file=foo.html.gz';rm -rf *'

my %data = split (/=/, $in);		# Make an array

my $file = $data{'file'};		# get the name of the requested file

print "Content-Type: text/html\n\n";
# print `echo '$file'`;			# debugging
print `zcat ~/WWW/'$file'`;		# quotes prevent nastys.

- -- 
No Microsoft products were used in any way for the creation of this message.
PGP Public key at http://mother.com/~ryan/ryan_at_mother_dot_com.asc
It is also on the servers: Key ID 0x72177BC7
Version: GnuPG v1.0.6 (GNU/Linux)
Comment: For info see http://www.gnupg.org

vox-tech mailing list

LUGOD Group on LinkedIn
Sign up for LUGOD event announcements
Your email address:
LUGOD Group on Facebook
'Like' LUGOD on Facebook:

Hosting provided by:
Sunset Systems
Sunset Systems offers preconfigured Linux systems, remote system administration and custom software development.

LUGOD: Linux Users' Group of Davis
PO Box 2082, Davis, CA 95617
Contact Us

LUGOD is a 501(c)7 non-profit organization
based in Davis, California
and serving the Sacramento area.
"Linux" is a trademark of Linus Torvalds.

Sponsored in part by:
Appahost Applications
For a significant contribution towards our projector, and a generous donation to allow us to continue meeting at the Davis Library.