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Showing posts with the label hexadecimal

An explanation of webserver logs that contain requests such as "\x16\x03\x01"

Recently I have started coming across somewhat unusual entries in the access and error logs for a few of the Apache web servers that I am responsible for maintaining. The entries look like this: - - [03/Nov/2015:13:56:23 -0500] "\x16\x03\x02\x01o\x01" 400 226 "-" "-" Here is another example: - - [03/Nov/2015:23:48:54 -0500] "\x16\x03\x01" 400 226 "-" "-" These errors will be generated on a website configured to use SSL - and in fact, error messages similar to these can be generated by misconfiguring SSL for your website. This error message, for instance, can indicate an attempt to access Apache through SSL while the OpenSSL engine is either disabled or misconfigured: Invalid method in request \x80g\x01\x03 Connections that generate that error would not be successful. This post, however, assumes that your website is working normally when used normally. So what gives? The error indicates