Mar 27, 2026 - For details about updated CVE-2025-53521 (BIG-IP APM vulnerability), refer to K000156741.

Forum Discussion

JG's avatar
JG
Icon for Cumulonimbus rankCumulonimbus
Nov 25, 2018

ASM: "Illegal Request"

I have come across a weird problem. A user access was blocked, with a support ID displayed. After searching the event log withe the support ID, I found that there was no learning suggestion for the a...
ASM Advanced WAF
illegal request
security
unblock
Wackitron_36350's avatar
Wackitron_36350
Icon for Altocumulus rankAltocumulus
Nov 25, 2018

That’s weird. It should show the violation it caused. BTW, 

illegal request is like it’s Flagged and but not Blocked
. Best solution here would be to recreate the issue and look up the event logs for the violation it caused. Like illegal uri, illegal param, cookie hijack, session hijack, etc. so we need to know to the violation to poke the hole in ASM policy.