centos7 Archives - Michael Altfield's Tech Blog

Hardening Guide for phpList

By Michael Altfield, on February 14th, 2020

This post will outline recommended steps to harden phpList after install to make it reasonably secure.

phpList is the most popular open-source software for managing mailing lists. Like wordpress, they have a phplist.com for paid hosting services and phplist.org for free self-hosting.

Earlier this week, it was announced that phpList had a critical security vulnerability permitting an attacker to bypass authentication and login as an administrator using an incorrect & carefully-crafted password in some cases. This bug is a result of the fact that [a] PHP is a loosely typed language and [b] the phpList team was using the ‘==‘ operator to test for equality of the user’s hashed password against the DB. This security pitfall has been known in PHP since at least 2010 (a decade ago!), but I’m sure the same mistake will be made again..

Indeed, security is porous. There’s no such thing as 100% vulnerability-free code, and phpList is no exception. But if we’re careful in adding layers of security to our infrastructure, then we might be able to protect ourselves from certain 0-days.

That said, here’s my recommended steps to making your phpList install reasonably secure.

Michael Altfield

Hi, I’m Michael Altfield. I write articles
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HPKP Best Practices for Let’s Encrypt

By Michael Altfield, on September 5th, 2017

This post describes how to generate a few backup public key hashes to add to your HTTP Public Key Pinning (HPKP) config that might save you from bricking your domain if Let’s Encrypt ever gets untrusted like StartCom did.

If you have a healthy distrust of the X.509 PKI trust model, then you’ve probably heard of HPKP (and probably also HSTS & CAA). Website certificate pinning was a trend first started by google, who hard-coded a pin of their certificates in their Chrome browser. Eventually, google helped build a more standardized pinning method under RFC 7469. And today, it’s supported by Chrome, Firefox, and Opera.

Pinning is a great TOFU improvement to https, but–if misconfigured–you could “brick” your domain–making it so that your client’s browsers will refuse to let them access your site for months or years (interestingly, this has also caused some security experts to think of how HPKP could be abused in ransom-ware). Therefore, it’s a good idea to follow a few HPKP Best Practices.

Michael Altfield

Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡

About Michael

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