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

Forum Discussion

babu_7813's avatar
babu_7813
Icon for Nimbostratus rankNimbostratus
May 19, 2014

Seeing continous "Request length exceeds defined buffer size" alert.

I am really wondering why F5 ASM trigger an alert " Request Length exceeds defined buffer size" for OWA traffic. As you said in your update, i have set 1000000 value in Click Application Security --...
ASM Advanced WAF
BIG-IP Access Policy Manager (APM)
deployment
security
mimlo_61970's avatar
mimlo_61970
Icon for Cumulonimbus rankCumulonimbus
May 19, 2014

See http://support.f5.com/kb/en-us/solutions/public/14000/000/sol14034.html for more information.

 

Basically your request (1073741824 based on the content length) was larger than the configured size of 10000000. The default is to block requests that exceed the buffer size. You can set EnableASMByPass to 1 to allow these requests through, but without ASM inspection.

 

You can also disable the violation under Policy, Blocking, Settings and uncheck "Request length exceeds defined buffer size"