McAfee HISCDE-AB-IA Product Guide - Page 62

With the control channel open, the client communicates with the FTP server. The firewall parses

the PORT command in the packet and creates a second entry in the state table to allow the

data connection.

When the FTP server is in active mode, it opens the data connection; in passive mode, the

client initiates the connection. When the FTP server receives the first data transfer command

(LIST), it opens the data connection toward the client and transfers the data. The data channel

is closed after the transmission is completed.

The combination of the control connection and one or more data connections is called a session,

and FTP dynamic rules are sometimes referred to as session rules. The session remains

established until its control channel entry is deleted from the state table. During the periodic

cleanup of the table, if a session’s control channel has been deleted, all data connections are

subsequently deleted.

Stateful protocol tracking

The types of protocol connections monitored by the stateful firewall and how they are handled

are summarized here.

Description of handling

Protocol

A UDP connection is added to the state table when a matching static rule is found and the action

from the rule is Allow. Generic UDP connections, which carry Application-Level protocols unknown

UDP

to the firewall, remain in the state table as long as the connection is not idle longer than the specified

timeout period.

Only ICMP Echo Request and Echo Reply message types are tracked.

NOTE:

In contrast to the reliable, connection-oriented TCP protocol, UDP and ICMPv4/v6 are less

reliable, connectionless protocols. To secure these protocols, the firewall considers generic UDP

ICMPv4/v6

and ICMP connections to be virtual connections, held only as long as the connection is not idle

longer than the timeout period specified for the connection. The timeout for virtual connections is

set in the Firewall Options policy.

When using IPv6, stateful firewall functionality is supported only on Windows Vista and later

platforms.

TCP protocol works on the S3-way handshake. When a client computer initiates a new connection,

it sends a packet to its target with a SYN bit that is set, indicating a new connection. The target

TCP

responds by sending a packet to the client with a SYN-ACK bit set. The client responds then by

sending a packet with an ACK bit set and the stateful connection is established. All outgoing packets

are allowed, but only incoming packets that are part of the established connection are allowed. An

exception is when the firewall first queries the TCP protocol and adds all pre-existing connections

that match the static rules. Pre-existing connections without a matching static rule are blocked. The

TCP connection timeout, which is set in the Firewall Options policy, is enforced only when the

connection is not established. A second or forced TCP timeout applies to established TCP connections

only. This timeout is controlled by a registry setting and has a default value of one hour. Every four

minutes the firewall queries the TCP stack and discards connections that are not reported by TCP.

Query/response matching ensures DNS responses are only allowed to the local port that originated

the query and only from a remote IP address that has been queried within the UDP Virtual Connection

Timeout interval. Incoming DNS responses are allowed if:

DNS

•

The connection in the state table has not expired.

•

The response comes from the same remote IP address and port where the request was sent.

Query/response matching ensures that return packets are allowed only for legitimate queries, Thus

incoming DHCP responses are allowed if:

DHCP

•

The connection in the state table has not expired.

•

The response transaction ID matches the one from the request.

Configuring Firewall Policies

Overview of Firewall policies

McAfee Host Intrusion Prevention 8.0 Product Guide for ePolicy Orchestrator 4.5

62

Section	Page
Contents	3
Introducing Host Intrusion Prevention	7
Host IPS protection	7
Host IPS policies	8
Host IPS policy management	9
Host IPS policy tracking and tuning	10
Managing Your Protection	12
Information management	12
Host IPS dashboards	12
Host IPS queries	13
Predefined and custom queries to analyze your protection	13
Policy management	16
Where to find policies	16
Configuring polices	17
Creating a new policy	18
Changing policy assignment	18
Default protection and tuning	18
Clients and planning your deployment	19
Client data and what it tells you	19
Adaptive mode	20
FAQ — Adaptive mode	21
Host IPS policy migration	22
System management	23
Host IPS permission sets	23
Assigning permission sets	24
Host IPS server tasks	25
Host IPS event responses	26
Tips on using automatic responses	26
Host IPS protection updates	27
Checking in update packages	27
Checking in packages manually	28
Updating clients with content	28
Updating content from the client	28
Configuring IPS Policies	29
Overview of IPS policies	29
Methods for delivery of IPS protection	30
Signatures	31
Behavioral rules	32
Reactions	32
Exceptions	32
Application protection rules	33
Events	33
Enable IPS protection	33
Configuring the IPS Options policy	34
Set the reaction for IPS signatures	35
Configuring the IPS Protection policy	36
Define IPS protection	36
Configuring the IPS Rules policy	37
Assigning multiple instances of the policy	37
FAQ — Multiple-instance policies	38
How IPS signatures work	39
Configuring IPS signatures	40
Creating custom signatures	41
Creating custom signatures with a wizard	42
FAQ — Use of wildcards in IPS Rules	42
How IPS application protection rules work	43
Configuring IPS application protection rules	45
Creating application protection rules	45
How IPS exceptions work	46
Configuring IPS exceptions	46
Creating exception rules	47
Monitor IPS events	47
Managing IPS events	48
Creating an exception from an event	49
Creating a trusted application from an event	50
Monitor IPS client rules	50
Managing IPS client rules	50
Configuring Firewall Policies	52
Overview of Firewall policies	52
How firewall rules work	53
Firewall protocols	53
How firewall rule groups work	55
Firewall rule group connection isolation	56
How the Host IPS catalog works	58
Firewall stateful packet filtering and inspection	59
Firewall state table	60
How stateful filtering works	60
How stateful packet inspection works	61
Stateful protocol tracking	62
How learn and adaptive modes affect the firewall	63
Firewall client rules	64
Enable firewall protection	64
Configuring the Firewall Options policy	65
FAQ — McAfee TrustedSource and the firewall	66
Define firewall protection	67
Configuring the Firewall Rules policy	68
Creating and editing firewall rules	69
Creating and editing firewall rule groups	69
Creating connection isolation groups	70
Blocking DNS traffic	70
Using the Host IPS catalog	70
Managing firewall client rules	71
FAQ — Use of wildcards in Firewall Rules	72
Configuring General Policies	73
Overview of General policies	73
Define client functionality	74
Configuring a Client UI policy	74
Setting Client UI general options	75
Setting Client UI advanced options and passwords	75
Creating passwords on a per system basis	76
Setting Client UI troubleshooting options	76
Define trusted networks	77
Configuring a Trusted Networks policy	78
Define trusted applications	78
Configuring a Trusted Applications policy	79
Creating and editing Trusted Application rules	79
Assigning multiple instances of the policy	80
Working with Host Intrusion Prevention Clients	81
Overview of the Windows client	81
System tray icon menu	81
Client console for Windows clients	83
Unlocking the Windows client interface	83
Setting client UI options	83
Troubleshooting the Windows client	84
Setting options for IPS logging	85
Settings options for Firewall logging	85
Disabling Host IPS engines	85
Windows client alerts	86
Responding to Intrusion alerts	86
Responding to Firewall alerts	87
Responding to Spoof Detected alerts	87
About the IPS Policy tab	88
Customizing IPS Policy options	88
Creating and editing IPS Policy exception rules	89
About the Firewall Policy tab	89
Customizing Firewall Policy options	90
Creating and editing Firewall rules	90
About the Blocked Hosts tab	91
Editing the Blocked Hosts list	92
About the Application Protection List tab	92
About the Activity Log tab	93
Customizing Activity Log options	93
Overview of the Solaris client	94
Policy enforcement with the Solaris client	94
Troubleshooting the Solaris client	95
Verifying Solaris installation files	96
Verifying the Solaris client is running	96
Stopping the Solaris client	96
Restarting the Solaris client	96
Overview of the Linux client	97
Policy enforcement with the Linux client	97
Notes about the Linux client	97
Troubleshooting the Linux client	98
Verifying Linux installation files	99
Verifying the Linux client is running	99
Stopping the Linux client	99
Restarting the Linux client	99
Appendix A — Writing Custom Signatures and Exceptions	101
Rule structure	101
Common sections	102
Optional common sections	104
Wildcards and variables	104
Windows custom signatures	107
Windows class Buffer Overflow	107
Windows class Files	108
Windows class Hook	111
Windows class Illegal Host IPS API Use	112
Windows class Illegal Use	113
Windows class Isapi (HTTP)	113
Windows class Program	116
Windows class Registry	117
Windows class Services	120
Windows class SQL	122
Classes and directives per Windows platform	123
Non-Windows custom signatures	127
Solaris/Linux class UNIX_file	127
Solaris/Linux class UNIX_apache (HTTP)	130
Solaris/Linux class UNIX_Misc	131
Solaris class UNIX_bo	132
Solaris class UNIX_map	133
Solaris class UNIX_GUID	133
Classes and directives per UNIX platform	134
Appendix B — Troubleshooting	136
General issues	136
Host IPS logs	141
Clientcontrol.exe utility	144

McAfee HISCDE-AB-IA Product Guide - Page 62

Stateful protocol tracking, cleanup of the table, if a session's control channel has been deleted

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