Go to main content

Textpattern CMS support forum

You are not logged in. Register | Login | Help

#1 Yesterday 18:57:51

skewray
Member
From: Sunny Southern California
Registered: 2013-04-25
Posts: 288
Website Mastodon

Captcha Bypass

About 4 or 5 days ago, I added a “captcha” to my website, sitting between Apache and Txp. For blog entries and file downloads, it presents a button to press before proceeding. So far, it stops about 98.5% of the access attempts. I’d call that a success! I have also seen it bypassed already:

  • Broadcom server (Google cloud sublet) loads captcha page with HTTP/1.1
  • 5 seconds later, reloads captcha page with HTTP/2
  • 1 second later, loads favicon with HTTP/2
  • 4 seconds later, presses button and loads page with all resources using HTTP/3
  • 10 hours later, returns with different nearby Broadcom server IP address, presses button, and loads page using HTTP/3. Loads no other resources.

#mildlyinteresting

Since /file_download/ is served through Txp, I use the same system to prevent deep-linking to files. Images are more complicated, since some are OpenGraph images, and htaccess doesn’t know which are which without a specific list to be maintained – yuck.

Offline

#2 Today 02:22:14

colak
Admin
From: Cyprus
Registered: 2004-11-20
Posts: 9,436
Website GitHub Mastodon Twitter

Re: Captcha Bypass

Just a heads up that there are open source captcha alternatives. ie


Yiannis
——————————
NeMe | hblack.art | EMAP | A Sea change | Toolkit of Care
I do my best editing after I click on the submit button.

Offline

#3 Today 02:48:30

skewray
Member
From: Sunny Southern California
Registered: 2013-04-25
Posts: 288
Website Mastodon

Re: Captcha Bypass

This is 69 lines of php+html and works fine for its intended purpose. I am having a hard time believing anything else will be easier to maintain. Moving the html part into Txp will make it even smaller.

Offline

Board footer

Powered by FluxBB