Hi,
As per ASA Syslog System Messages, the error code 415014 most probably related or indicate an attack of that there is not an HTTP server on the server-side of the connection. This message was issued when the http-map strict-http command is configured and a more than unanswered 10 HTTP requests have been seen on a single connection.
From ASA 7.1 Syslog system messages (similar to 7.0), it says that:
http://www.cisco.com/en/US/partner/products/ps6120/products_system_message_guide_chapter09186a008055fd2b.html#wp3047941
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415014
Error Message %PIX|ASA-4-415014:internal_sig_id Maximum of 10 unanswered HTTP requests
exceeded from source_address to dest_address
Explanation This message is issued when the http-map strict-http command is configured and a more than unanswered 10 HTTP requests have been seen on a single connection.
internal_sig_idThis an internal "policy number" that can be used by developers to identify the specific policy that triggered the alert.
actionThis can contain either: "Reset -" or "Drop -" depending upon the user-configured action. If the action is "log" then the null string "" is passed.
source_addressThe source address of the packet in which the final unanswered request was detected.
dest_addressThe destination address of the packet in which the final unanswered request was detected.
Recommended Action Someone has sent multiple HTTP request messages that are not being answered. This may indicate an attack of that there is not an HTTP server on the server-side of the connection.
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Hope this helps.
Rgds,
AK