Network and system security

IEEE 802.11 is a set of standards for implementing wireless local area network (WLAN) computer communication in the 2.4, 3.6, 5 and 60 GHz frequency bands. They are created and maintained by the IEEE LAN/MAN Standards Committee (IEEE 802). The base version of the standard was released in 1997 and has had subsequent amendments. These standards provide the basis for wireless network products using the Wi-Fi brand.

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The Web has become the visible interface of the Internet Many corporations now use the Web for advertising, marketing and sales Web servers might be easy to use but… Complicated to configure correctly and difficult to build without security flaws They can serve as a security hole by which an adversary might be able to access other data and computer systems

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An integrated collection of tools for network monitoring and control. Single operator interface Minimal amount of separate equipment. Software and network communications capability built into the existing equipment SNMP key elements: Management station Managament agent Management information base Network Management protocol Get, Set and Notify

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Security Attack: Any action that compromises the security of information. Security Mechanism: A mechanism that is designed to detect, prevent, or recover from a security attack. Security Service: A service that enhances the security of data processing systems and information transfers. A security service makes use of one or more security mechanisms.

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Users and Security Security domain The database administrator defines the names of the users who are allowed to access a database. A security domain defines the settings that apply to the user. Authentication mechanism A user who requires access to the database can be authenticated by one of the following: Data dictionary Operating system Network The means of authentication is specified at the time the user is defined in the database and can be altered later. This lesson covers authentication by database and by operating system only.

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We now begin our look at building protocols using the basic tools that we have discussed. The discussion in this lecture will focus on issues of key establishment and the associated notion of authentication These protocols are not real, but instead are meant to serve just as a high-level survey Later lectures will go into specific protocols and will uncover practical challenges faced when implementing these protocols

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The Devil said to Daniel Webster: "Set me a task I can't carry out, and I'll give you anything in the world you ask for." Daniel Webster: "Fair enough. Prove that for n greater than 2, the equation an + bn = cn has no non-trivial solution in the integers." They agreed on a three-day period for the labor, and the Devil disappeared. At the end of three days, the Devil presented himself, haggard, jumpy, biting his lip. Daniel Webster said to him, "Well, how did you do at my task? Did you prove the theorem?' "Eh? No . . . no, I haven't...

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Protect web content from those who don’t have a “need to know” Require users to authenticate using a userid/password before they are allowed access to certain URLs HTTP/1.1 requires that when a user makes a request for a protected resource the server responds with a authentication request header WWW-Authenticate contains enough pertinent information to carry out a “challenge-response” session between the user and the server

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Used to connect two private networks together via the Internet Used to connect remote users to a private network via the Internet This could be done by opening your firewall to the LAN networking protocols (NETBIOS, NFS NetWare, AppleTalk)) But… it would also make those protocols available to any one on the Internet and they could come into your LAN at will Effectively make the whole Internet your LAN Exposes all of your data Anyone can easily take advantage of vulnerabilities in your internal hosts No privacy Better solution is to use a VPN in conjunction with your firewall ...

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Security-Enhanced Linux (SELinux) is an implementation of mandatory access control using Linux Security Modules (LSM) in the Linux kernel, based on the principle of least privilege. It is not a Linux distribution, but rather a set of modifications that can be applied to Unix-like operating systems, such as Linux and BSD.

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Developed 1996 as a teaching tool Santa Clara University\ Prof. Edward Schaefer Takes an 8-bit block plaintext, a 10 –bit key and produces an 8-bit block of ciphertext Decryption takes the 8-bit block of ciphertext, the same 10-bit key and produces the original 8-bit block of plaintext

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cacls /T /E /G administrator:F d:\users\*.* Cacls will add Full Control for the adminsitrator account all files and subfolders in the Users folder of the D:\ drive. cacls /T /E /R Everyone d:\users Cacls will remove all permissions for the 'Everyone' group in all files and subfolders in the Users folder of the D:\ drive. Be sure to use the /E switch when you are just making modifications to a specific account or group. Without the /E switch, your settings will replace the current security with only what is specified. ...

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Security Service – a service provided by a protocol layer of communicating open systems, which ensures adequate security of the systems or of data transfers RFC 2828 – a processing or communication service that is provided by a system to give a specific kind of protection to system resources; security services implement security policies and are implemented bt security mechanisms.

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Raw Sockets let you program at just above the network (IP) layer You could program at the IP level using the IP API but you can’t get at ICMP Raw Sockets expose ICMP you get a Raw Packet and populate the entire packet yourself for high level protocols like TCP and UDP you lose all of the functionality implemented in those layers choosing to use a Raw Socket must be weighed carefully Raw Sockets can be dangerous Raw Sockets can be against the law http://www.kumite.com/rsnbrgr/rob/grcspoof/cnn/ ...

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Part of an overall Firewall strategy Sits between the local network and the external network Originally used primarily as a caching strategy to minimize outgoing URL requests and increase perceived browser performance Primary mission is now to insure anonymity of internal users Still used for caching of frequently requested files Also used for content filtering Acts as a go-between, submitting your requests to the external network Requests are translated from your IP address to the Proxy’s IP address E-mail addresses of internal users are removed from request headers Cause an actual brea...

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Used to communicate IP status and error messages between hosts and routers Uses IP to route its messages between hosts Must be implemented with IP remember, IP is just a packet delivery system transmits and routes datagrams from sources to destinations through a series of interconnected networks it has a checksum in the IP header to detect lost bits no error detection on the datagram payload though but has no native mechanism for source host notification This is where ICMP comes in its used to report IP errors to the source host ICMP data is carried as the payload of an IP datagram specifie...

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One of the most common ways to mount a Distributed Denial of Service attacks is done via networks of zombie computers taking instructions from a central point Early net were controlled via proprietary software written by the network owner Today they are mostly controlled by an IRC channel This makes it easier to control the network and easier for the owner to hide

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Forge a connection to a host running chargen and have it send useless chargen data to the echo server on another makes the 2 services so busy that the host may crash or be too busy to respond to normal traffic Defense: configure only services that are absolutely necessary (chargen and echo have no business running on a production server)

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Computer Software, Systems and Networks are complex growing systems. They constantly evolve and their ability to be understood and recreated as well as proven integrity issues are critical to an organizations health and security.

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khái quát lỗi Secure Network Operations, Inc. http://www.secnetops.com/research Strategic Reconnaissance Team research secnetops com Team Lead Contact kf secnetops com. Our Mission: Operations offers expertise in Networking, Intrusion Detection Systems (IDS), Software Security Validation, and Corporate/Private Network Security. Our mission is to facilitate a secure and reliable Internet and inter-enterprise communications infrastructure through the products and services we offer.

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