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CWE-291: Trusting Self-reported IP Address

 
Trusting Self-reported IP Address
Compound Element ID: 291 (Compound Element Variant: Composite)Status: Incomplete
+ Description

Description Summary

The use of IP addresses as authentication is flawed and can easily be spoofed by malicious users.

Extended Description

As IP addresses can be easily spoofed, they do not constitute a valid authentication mechanism. Alternate methods should be used if significant authentication is necessary.

+ Time of Introduction
  • Architecture and Design
+ Applicable Platforms

Languages

All

+ Common Consequences
ScopeEffect
Access Control
Non-Repudiation

Technical Impact: Hide activities; Gain privileges / assume identity

Malicious users can fake authentication information, impersonating any IP address.

+ Likelihood of Exploit

High

+ Demonstrative Examples

Example 1

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

(Bad Code)
Example Languages: C and C++ 
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) {
memset(msg, 0x0, MAX_MSG);
clilen = sizeof(cli);
if (inet_ntoa(cli.sin_addr)==getTrustedAddress()) {
n = recvfrom(sd, msg, MAX_MSG, 0, (struct sockaddr *) & cli, &clilen);
}
}
(Bad Code)
Example Language: Java 
while(true) {
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)) {
out = secret.getBytes();
DatagramPacket sp =new DatagramPacket(out,out.length, IPAddress, port); outSock.send(sp);
}
}

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

+ Potential Mitigations

Phase: Architecture and Design

Use other means of identity verification that cannot be simply spoofed. Possibilities include a username/password or certificate.

+ Weakness Ordinalities
OrdinalityDescription
Resultant
(where the weakness is typically related to the presence of some other weaknesses)
+ Relationships
NatureTypeIDNameView(s) this relationship pertains toView(s)
RequiresWeakness BaseWeakness Base348Use of Less Trusted Source
Research Concepts1000
RequiresWeakness BaseWeakness Base471Modification of Assumed-Immutable Data (MAID)
Research Concepts1000
ChildOfWeakness BaseWeakness Base290Authentication Bypass by Spoofing
Development Concepts (primary)699
Research Concepts (primary)1000
+ Causal Nature

Explicit

+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
CLASPTrusting self-reported IP address
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
CLASPExternally Mined
Modifications
Modification DateModifierOrganizationSource
2008-09-08CWE Content TeamMITREInternal
updated Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings, Weakness_Ordinalities
2010-02-16CWE Content TeamMITREInternal
updated Description, Other_Notes
2011-06-01CWE Content TeamMITREInternal
updated Common_Consequences, Demonstrative_Examples
2012-05-11CWE Content TeamMITREInternal
updated Demonstrative_Examples, Relationships
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Page Last Updated: February 20, 2013
 

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