A domain name server translates a domain name (such as www.example.com) into an IP address that Internet hosts use to contact Internet resources. An adversary modifies a public DNS cache to cause certain names to resolve to incorrect addresses that the adversary specifies. The result is that client applications that rely upon the targeted cache for domain name resolution will be directed not to the actual address of the specified domain name but to some other address. Adversaries can use this to herd clients to sites that install malware on the victim's computer or to masquerade as part of a Pharming attack.
Likelihood Of Attack
High
Typical Severity
High
Relationships
This table shows the other attack patterns and high level categories that are related to this attack pattern. These relationships are defined as ChildOf and ParentOf, and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as CanFollow, PeerOf, and CanAlsoBe are defined to show similar attack patterns that the user may want to explore.
Nature
Type
ID
Name
ChildOf
Standard Attack Pattern - A standard level attack pattern in CAPEC is focused on a specific methodology or technique used in an attack. It is often seen as a singular piece of a fully executed attack. A standard attack pattern is meant to provide sufficient details to understand the specific technique and how it attempts to accomplish a desired goal. A standard level attack pattern is a specific type of a more abstract meta level attack pattern.
Standard Attack Pattern - A standard level attack pattern in CAPEC is focused on a specific methodology or technique used in an attack. It is often seen as a singular piece of a fully executed attack. A standard attack pattern is meant to provide sufficient details to understand the specific technique and how it attempts to accomplish a desired goal. A standard level attack pattern is a specific type of a more abstract meta level attack pattern.
Explore resolver caches: Check DNS caches on local DNS server and client's browser with DNS cache enabled.
Techniques
Run tools that check the resolver cache in the memory to see if it contains a target DNS entry.
Figure out if the client's browser has DNS cache enabled.
Experiment
Attempt sending crafted records to DNS cache: A request is sent to the authoritative server for target website and wait for the iterative name resolver. An adversary sends bogus request to the DNS local server, and then floods responses that trick a DNS cache to remember malicious responses, which are wrong answers of DNS query.
Techniques
Adversary must know the transaction ID by intercepting a DNS query, or sending a bogus query with known transaction ID.
If the transaction ID used to identify each query instance is randomized in some new DNS software, the attack must guess the transaction ID. Slow the response of the real DNS server by causing Denial-of-service. This gives adversaries enough time to guess transaction
Adversary crafts DNS response with the same transaction ID as in the request. The adversary sends out DNS responses before the authorized DNS server. This forces DNS local cache stores fake DNS response (wrong answer). The fake DNS responses usually include a malicious website's IP address.
Exploit
Redirect users to malicious website: As the adversary succeeds in exploiting the vulnerability, the victim connects to a malicious site using a good web site's domain name.
Techniques
Redirecting Web traffic to a site that looks enough like the original so as to not raise any suspicion.
Adversary-in-the-Middle (CAPEC-94) intercepts secure communication between two parties.
Prerequisites
A DNS cache must be vulnerable to some attack that allows the adversary to replace addresses in its lookup table.Client applications must trust the corrupted cashed values and utilize them for their domain name resolutions.
Skills Required
[Level: Medium]
To overwrite/modify targeted DNS cache
Resources Required
The adversary must have the resources to modify the targeted cache. In addition, in most cases the adversary will wish to host the sites to which users will be redirected, although in some cases redirecting to a third party site will accomplish the adversary's goals.
Mitigations
Configuration: Make sure your DNS servers have been updated to the latest versions
Configuration: UNIX services like rlogin, rsh/rcp, xhost, and nfs are all susceptible to wrong information being held in a cache. Care should be taken with these services so they do not rely upon DNS caches that have been exposed to the Internet.
Configuration: Disable client side DNS caching.
Example Instances
In this example, an adversary sends request to a local DNS server to look up www.example .com. The associated IP address of www.example.com is 1.3.5.7.
Local DNS usually caches IP addresses and do not go to remote DNS every time. Since the local record is not found, DNS server tries to connect to remote DNS for queries. However, before the remote DNS returns the right IP address 1.3.5.7, the adversary floods local DNS with crafted responses with IP address 2.4.6.8. The result is that 2.4.6.8 is stored in DNS cache. Meanwhile, 2.4.6.8 is associated with a malicious website www.maliciousexampsle.com
When users connect to www.example.com, the local DNS will direct it to www.maliciousexample.com, this works as part of a Pharming attack.
Related Weaknesses
A Related Weakness relationship associates a weakness with this attack pattern. Each association implies a weakness that must exist for a given attack to be successful. If multiple weaknesses are associated with the attack pattern, then any of the weaknesses (but not necessarily all) may be present for the attack to be successful. Each related weakness is identified by a CWE identifier.
Reliance on Reverse DNS Resolution for a Security-Critical Action
Taxonomy Mappings
CAPEC mappings to ATT&CK techniques leverage an inheritance model to streamline and minimize direct CAPEC/ATT&CK mappings. Inheritance of a mapping is indicated by text stating that the parent CAPEC has relevant ATT&CK mappings. Note that the ATT&CK Enterprise Framework does not use an inheritance model as part of the mapping to CAPEC.
Relevant to the ATT&CK taxonomy mapping (also see parent)
Description
This table shows the other attack patterns and high level categories that are related to this attack pattern. These relationships are defined as ChildOf and ParentOf, and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as CanFollow, PeerOf, and CanAlsoBe are defined to show similar attack patterns that the user may want to explore.
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