CWE-290: Authentication Bypass by Spoofing

CWE-290: Authentication Bypass by Spoofing | RadicalNotion.AI

Code examples

Illustrative examples from MITRE showing how the weakness appears in code.

The following code authenticates users.

Vulnerable example

java

String sourceIP = request.getRemoteAddr();

The authentication mechanism implemented relies on an IP address for source validation. If an attacker is able to spoof the IP, they may be able to bypass the authentication mechanism.

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

Vulnerable example

sd = socket(AF_INET, SOCK_DGRAM, 0);

Vulnerable example

java

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.

The following code samples use a DNS lookup in order to decide whether or not an inbound request is from a trusted host. If an attacker can poison the DNS cache, they can gain trusted status.

Vulnerable example

struct hostent *hp;struct in_addr myaddr;

Vulnerable example

java

String ip = request.getRemoteAddr();

Vulnerable example

csharp

IPAddress hostIPAddress = IPAddress.Parse(RemoteIpAddress);

IP addresses are more reliable than DNS names, but they can also be spoofed. Attackers can easily 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.

CWE-290: Authentication Bypass by Spoofing

Overview

Real-world CVEs

Common consequences

How it happens

When it is introduced

Code examples

Illustrative examples

Terminology & mappings

Mapped taxonomies

Attack patterns

Frequently asked questions

What is CWE-290?

What CVEs are caused by CWE-290?

What are the consequences of CWE-290?

Is CWE-290 actively exploited?

References

Stay ahead of CWE-290

Overview

Real-world CVEs

Common consequences

How it happens

When it is introduced

Code examples

Illustrative examples

Related weaknesses

Parent

Child

Peer

Related

Terminology & mappings

Mapped taxonomies

Attack patterns

Frequently asked questions

What is CWE-290?

What CVEs are caused by CWE-290?

What are the consequences of CWE-290?

Is CWE-290 actively exploited?

References

Stay ahead of CWE-290