CS 6035 - Exam 2 Flashcards
Packet filter firewalls can not prevent attacks that employ application-specific vulnerabilities or functions
(T/F)
True –> because packet filter firewalls do not examine upper-layer data, they cannot prevent attacks that employ application-specific vulnerabilities or functions.
For example, a packet filtering firewall cannot block specific application commands; if a packet filter firewall allows a given application, all functions available within the application will be permitted
A firewall can protect fully against internal threats, such as a disgruntled employee or an employee who unwittingly cooperates with an external attacker.
(T/F)
False
A Stateful Packet Inspection Firewall only allows incoming TCP traffic to high level ports for packets which fit the profile of an entry in its directory of outbound TCP packets
(T/F)
True
A simple packet filtering firewall must permit inbound network traffic on all high-numbers ports for TCP-based traffic filtering. This creates a vulnerability that can be exploited by unauthorized users.
A stateful packet inspection firewall tightens up the rules for TCP traffic by creating a directory of outbound TCP connections. Incoming traffic has to fit the profile of entries.
Internal firewalls usually provide two-way protection for the DMZ (demilitarized zone) network system
(T/F)
True
A botnet attack compromises the availability of a system but not its integrity
(T/F)
False
Which of the following is not used by packet filtering firewall rules?
- Source or destination IP address
- IP protocol field
- TCP port number
- TCP sequence number
TCP sequence number
A privilege - escalation exploit is malicious behavior which:
- Operates by changing system resources such as libraries, directories, registry settings, and user accounts
- Mails a copy of itself to address in the local system’s email address book
- Allows the hacker to access files outside the range of which a server application would normally need to access
- Obtains root access from a (non-root) user account
Obtains access from a (non-root) user account
A _____ vulnerability in a Web server allows the hacker to access files outside the range of what a server application user would normally need access to.
directory traversal
examples of types of malicious behavior addresses by a host-based IPS (HIPS)
You run a network firewall for a company that handles lots of text message traffic. Spammers occasionally try to trick your systems into sending text messages for them. You notice these incoming requests always contain a spoofed address that looks like an IP address internal to your network. What is the most effective countermeasure for you to take against the spoofers.
- Discard packets with an internal source address if that packet arrives on an internal interface
- Change settings in the browser so that they only send requests with their own ip address as the source address
- Modify the routers to block all external traffic
- Discard packets with an internal source address if the packet arrives on an external interface
Discard packets with an internal source address if the packet arrives on an external interface
Which of the following are examples of attacks that can be made on packet-filtering firewalls?
- IP address spoofing
- Fragment attacks
- Source routing attacks
- All of the above
- A & C
All of the above.
In the context of a network-based IPS (NIPS), _____ is a strategy used to identify malicious packets by scanning for attack signatures in a traffic stream, rather than individual packets.
Stateful matching
In the context of a network-based IPS (NIPS), _____ scans incoming packets for specific byte sequences (the signatures) stores in database of known attacks.
Pattern matching
In the context of a network-based IPS (NIPS), _____ looks for deviation from standards set forth in RFCs (remote function call).
Protocol anomaly
In the context of a network-based IPS (NIPS), _____ watches for unusual traffic activities, such as flood of UDP packets or a new service appearing on the network.
Traffic anomaly
In the context of a network-based IPS (NIPS), _____ develops baselines of normal traffic activity and throughput, and alerts on deviations from those baselines.
Statistical anomaly.
A bot is a computer compromised by malware and under the control of a bot master
(T/F)
True
The best defense against being an unwitting participant in a DDoS attack is to prevent your system from being compromised.
(T/F)
True
Botnet command-and-control must be centralize, i.e., all bots communicate with a central server(s).
(T/F)
False
Both static and dynamic analysis are needed in order to fully understand malware behaviors.
True
The domain name(s) of the command and control server(s) of botnet are pre-determined for the lifetime of the bot.
(T/F)
False
Some API attacks last for years before they are detected.
T/F
True
If we find that a botnet server is located in country X, we can be certain that criminals within country X control the botnet.
(T/F)
False
The firewall may be a single computer system or set of two or more systems that cooperate to perform the firewall function
(T/F)
True
A firewall can serve as the platform for IPSec.
T/F
True