IP spoofing, also known as IP address forgery or a host file hijack, is a hijacking technique in which a cracker masquerades as a trusted host to conceal his identity, spoof a Web site, hijack browsers, or gain access to a network.

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Can I trust the source IP of an HTTP request?

As far as I've understood, if you try to issue a HTTP request with a spoofed IP address, then the TCP handshake fails, so it's not possible to complete the HTTP request, because the SYN/ACK from the ...
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2answers
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IP Spoofing a threat?

Quick Security Question if i may. We have an internal Intranet system which is only accessible from a few internal vlans, our main external firewall blocks all access to the internal webserver – or ...
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IP Adress Spofing via ncat,nc etc [duplicate]

Possible Duplicate: Netcat IP Spoofing I want to ask one question to you. My friend and i playing game together.He is using below command this computer. ncat -u -c /bin/bash --allow ...
6
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1answer
567 views

Ingress RFC1918 spoofing: How to handle it?

I've seen packets originating from RFC1918 addresses from two fairly large european ISP's (ASN1257 & smaller ASN35706) coming in on eBGP transit links lately, and I'm a bit puzzled why it wouldn't ...
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4k views

How secure can IP based login be?

From several security books and sites I understand that IP-based security (with which I mean: user is verified only by IP address) is a bad idea. Our idea is not new: we want a one-time validation and ...
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5answers
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Is it trivial to bypass IP blocking?

There is a site with IP blocking. When a client makes too many invalid attempts when guessing e.g. password, then their IP address becomes blocked. I've heard about IP spoofing and similar attacks. ...
13
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2answers
4k views

Is IP spoofing relevant to TCP? Is it relevant for TLS or SSH?

I have read the TCP Connection Establishment on Wikipedia In brief the packets to start are SYN, with a (hopefully) random sequence number A from the client. SYN-ACK, responding, with A+1 and ...
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2answers
2k views

Why would the browser present the certificate for an unknown outside site?

The first time each day that I attempt click on the 'Mail' link from the Yahoo home page, my browser (Seamonkey) throws up a dialog with the title 'Secure connection failed'. The content in the ...
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1answer
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Spoofing email From address

Providing all legal measures are taken care of, what are some of the ways someone can spoof an email "From" field address and actually get the email to the recipient without spam filters getting in ...
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How easy/difficult is it to spoof DNS? Are some scenarios safer/more risky than others?

Practically speaking, how easy difficult is it to spoof DNS? What scenarios are more risky than others? For example: A phishing email or twitter link that attracts users to click a hyperlink A ...
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0answers
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Pages restricted to certain IPs, safe? [duplicate]

Possible Duplicate: In what scenarios is relying on source IP address as a security control acceptable/unacceptable? If a website has a page which only renders for certain IPs, is there ...
5
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3answers
625 views

Solaris: IP Spoofing Across Ethernet Ports

Given a Solaris machine with two network interfaces corresponding to the separate ethernet ports in the back. 0: 192.168.0.5/255.255.255.0 1: 192.168.1.5/255.255.255.0 with /etc/defaultrouter set ...
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1answer
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What kind of nefarious deeds can IP address Spoofing be used for? [duplicate]

Possible Duplicate: What security risks does IP spoofing bring? I found this article, which seems pretty good but was written in 2003 so I'm not sure how up to date it is. Can IP address ...
8
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4answers
1k views

How can a company reduce exposure to packet spoofing? What solution should exist, but doesn't?

I'd like to understand what anti-packet-spoofing technology exists (or should exist) to verify an inbound packet. Maybe this is as simple as a Cisco ACL, Firewall Rule, implemented at the network ...
8
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3answers
448 views

Verify a website user is behind corporate firewall?

We have a public ecommerce website hosted at our datacenter onsite. For people who are within the corporate firewall hitting the website I want to display profiling information about the request of ...
2
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1answer
441 views

IP Conflicts / Spoofing

Are there any products / os that behave differently when an duplicate IP address is detected. This may indicate an IP spoof ? Can TCP stack 'shutdown' or stop in order to protect itself ?
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Are there valid reasons for spoofing an address?

This is a corollary to the question Why don't ISPs filter on source address to prevent spoofing?. Are there valid reasons to spoof an address?