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in reply to Security techniques every programmer should know

Writing secure programs. Wow, that's a huge topic. Where to start? :-)

I suppose with some basic Perl references. The Camel Chapter 20 "Security" provides an excellent (and much more detailed than perlsec) overview of fundamental Perl security issues. This chapter is broken into: Handling Insecure Data, Detecting and Laundering Tainted Data, Defeating Taint Checking, Cleaning Up Your Environment, Accessing Commands and Files Under Reduced Privileges, Handling Timing Glitches (Unix Kernel Security Bugs, Handling Race Conditions, Temporary Files), Handling Insecure Code (Changing root, Safe compartments, Code Masquerading as Data).

The Perl Cookbook has recipes: 8.17 (Testing a File for Trustworthiness), 19.4 (Writing a Safe CGI Program), 19.5 (Executing Commands Without Shell Escapes).

Though the Safe module is described in the Camel, it's not safe according to Safe.pm considered unsafe?.

The venerable suidperl has apparently had all known insecurities plugged by Paul Szabo in Perl 5.8.4. However, "For new projects the core perl team would strongly recommend that you use dedicated, single purpose security tools such as sudo in preference to suidperl" (perl584delta).

Which leads me to an important general piece of security advice (simplifying outrageously): Keep up-to-date with the latest version of perl. Well, that's a bit over the top; keep an eye on security alerts and perldelta security bug fixes and upgrade your perl judiciously. Apart from Paul's heroic suidperl fixes, security bugs are being squashed all the time. For example, perl 5.8 introduced Hash Randomisation and ensuring that sort never goes O(n-squared). Despite these two important denial-of-service (DoS) improvements, Perl regular expressions remain a concern for DoS attacks, it being easy to write (and hard to detect) a regular expression that finishes after the heat death of the universe.

Application Security References

Static Program Analysis

Dynamic Program Analysis

General Security References

Perl Security References

CPAN Security

Perl Monks Nodes related to CPAN Security

CPAN and Package Manager Security:

Perl Monks Security Related Nodes

Classics:

String Eval vs Block Eval:

Taint Mode:

2022-2024

Earlier:

Two nodes with the same title :)

SQL related:

Golf :-)

Other

Updated: Many extra references were added long after the original reply was made.

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