CWE-291: Reliance on IP Address for Authentication

Description

The product uses an IP address for authentication.

Submission Date :

July 19, 2006, midnight

Modification Date :

2023-10-26 00:00:00+00:00

Organization :

MITRE

Extended Description

IP addresses can be easily spoofed. Attackers can forge the source IP address of the packets they send, but response packets will return to the forged IP address. To see the response packets, the attacker has to sniff the traffic between the victim machine and the forged IP address. In order to accomplish the required sniffing, attackers typically attempt to locate themselves on the same subnet as the victim machine. Attackers may be able to circumvent this requirement by using source routing, but source routing is disabled across much of the Internet today. In summary, IP address verification can be a useful part of an authentication scheme, but it should not be the single factor required for authentication.

Example Vulnerable Codes

Example - 1

Both of these examples check if a request is from a trusted address before responding to the request.



n = recvfrom(sd, msg, MAX_MSG, 0, (struct sockaddr *) & cli, &clilen);memset(msg, 0x0, MAX_MSG);clilen = sizeof(cli);if (inet_ntoa(cli.sin_addr)==getTrustedAddress()) {}sd = socket(AF_INET, SOCK_DGRAM, 0);serv.sin_family = AF_INET;serv.sin_addr.s_addr = htonl(INADDR_ANY);servr.sin_port = htons(1008);bind(sd, (struct sockaddr *) & serv, sizeof(serv));while (1) {}



out = secret.getBytes();DatagramPacket sp =new DatagramPacket(out,out.length, IPAddress, port); outSock.send(sp);DatagramPacket rp=new DatagramPacket(rData,rData.length);outSock.receive(rp);String in = new String(p.getData(),0, rp.getLength());InetAddress clientIPAddress = rp.getAddress();int port = rp.getPort();if (isTrustedAddress(clientIPAddress) & secretKey.equals(in)) {}while(true) {}

The code only verifies the address as stored in the request packet. An attacker can spoof this address, thus impersonating a trusted client.

Related Weaknesses

This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined to give an overview of the different insight to similar items that may exist at higher and lower levels of abstraction.

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