Forum Discussion

Yozzer's avatar
Yozzer
Icon for Nimbostratus rankNimbostratus
Apr 29, 2021

ASM blocked page redirect

When triggering an ASM signature we have a custom blocked page returned to the user who is then redirected to another page on the web server so that their session cookie is invalidated.   Attacke...
application delivery
ASM Advanced WAF
iRules
security
  • AlexBCT's avatar
    AlexBCT
    May 02, 2021

    I think via an iRule, you should be able to do this with the SIDEBAND command (https://clouddocs.f5.com/api/irules/SIDEBAND.html) - take the HTTP url that you currently have included in the redirect page, and should be able to use this in the iRule. (no personal experience with this one though).

     

    Alternatively, are you familiar with ASM's Session Awareness functions? (Security  ››  Application Security : Sessions and Logins : Session Tracking) You can enforce the session management on the ASM box, rather than on the backend webserver. Once enabled, you can also tell the F5 to block off particular sessions, IP's or usernames after X violations. Personally I prefer this option above session management on the backend server.

spalande's avatar
spalande
Icon for Nacreous rankNacreous
Apr 30, 2021

When F5 ASM sends the block page, it includes Connection: close header by default. If it's not included, you can add it in the custom block page settings. Shouldn't that be enough to delete/invalidate session cookies? May be you can capture some http trace and validate this behaviour.