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<p class="MsoNormal">Hi all,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I’m trying to figure out what the requests are that are resulting in the following Varnish responses and how to block them:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">* << Request >> 39071654
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">- Begin req 39071653 rxreq<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">- Timestamp Start: 1721059686.537197 0.000000 0.000000<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">- Timestamp Req: 1721059686.537197 0.000000 0.000000<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">- BogoHeader Illegal char 0x20 in header name<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">- HttpGarbage "GET%00"<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">- RespProtocol HTTP/1.1<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">- RespStatus 400<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">- RespReason Bad Request<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">- ReqAcct 535 0 535 28 0 28<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">- End<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">These are on AWS EC2 instances that are behind an Application Load Balancer (ALB) that is connected to a Web Application Firewall (WAF), so in theory I should be able to figure out a rule to add to the WAF to block these. I’d just need
to get more information to do so, and AWS support could probably help, but I wanted to check here first if there’s any way to get further information about such requests out of Varnish.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">FWIW, the 0x20 is a space character, but there are also similar requests reporting 0x09 (horizontal tab) characters.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">Justin<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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