comment on

I do not know why your script dies, but are you sure you really want to use it? It seems very insecure.

It makes cookies with the user's password, which as a result will be sent around all the time. (Actually, the MD5 of a password, which is better, but still not good)

It is vulnerable to SQL injection attacks:

my $sth = $dbh->prepare("SELECT * FROM $users_table WHERE username = '
+$username' AND user_password = '$userpass'");
        $sth->execute;
[download]

A user called ' or 1=1 -- could probably login without a password. That should really be:

my $sth = $dbh->prepare("SELECT * FROM $users_table WHERE username = ?
+ AND user_password = ?");
$sth->execute($username, $userpass);
[download]

It looks like any user with a cookie "user_id" is assumed to be logged in. It is easy for users to make such a cookie by themselves.

In reply to Re: Debugging a login script using MySQL by Thilosophy
in thread Debugging a login script using MySQL by coldfingertips

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		`&`
	<		`<`
	>		`>`
	[		`[`
	]		`]`

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.