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CAPEC-55: Rainbow Table Password Cracking |
Description An attacker gets access to the database table where hashes of passwords are stored. They then use a rainbow table of pre-computed hash chains to attempt to look up the original password. Once the original password corresponding to the hash is obtained, the attacker uses the original password to gain access to the system. Extended Description A password rainbow table stores hash chains for various passwords. A password chain is computed, starting from the original password, P, via a reduce(compression) function R and a hash function H. A recurrence relation exists where Xi+1 = R(H(Xi)), X0 = P. Then the hash chain of length n for the original password P can be formed: X1, X2, X3, ... , Xn-2, Xn-1, Xn, H(Xn). P and H(Xn) are then stored together in the rainbow table. Constructing the rainbow tables takes a very long time and is computationally expensive. A separate table needs to be constructed for the various hash algorithms (e.g. SHA1, MD5, etc.). However, once a rainbow table is computed, it can be very effective in cracking the passwords that have been hashed without the use of salt. Likelihood Of Attack Typical Severity Execution Flow Explore Determine application's/system's password policy: Determine the password policies of the target application/system. | Techniques |
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| Determine minimum and maximum allowed password lengths. | | Determine format of allowed passwords (whether they are required or allowed to contain numbers, special characters, etc.). | | Determine account lockout policy (a strict account lockout policy will prevent brute force attacks). |
Obtain password hashes: An attacker gets access to the database table storing hashes of passwords or potentially just discovers a hash of an individual password. | Techniques |
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| Obtain copy of database table or flat file containing password hashes (by breaking access controls, using SQL Injection, etc.) | | Obtain password hashes from platform-specific storage locations (e.g. Windows registry) | | Sniff network packets containing password hashes. |
Exploit Run rainbow table-based password cracking tool: An attacker finds or writes a password cracking tool that uses a previously computed rainbow table for the right hashing algorithm. It helps if the attacker knows what hashing algorithm was used by the password system. | Techniques |
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| Run rainbow table-based password cracking tool such as Ophcrack or RainbowCrack. Reduction function must depend on application's/system's password policy. |
Prerequisites
| Hash of the original password is available to the attacker. For a better chance of success, an attacker should have more than one hash of the original password, and ideally the whole table. |
| Salt was not used to create the hash of the original password. Otherwise the rainbow tables have to be re-computed, which is very expensive and will make the attack effectively infeasible (especially if salt was added in iterations). |
| The system uses one factor password based authentication. |
Skills Required
[Level: Low] A variety of password cracking tools are available that can leverage a rainbow table. The more difficult part is to obtain the password hash(es) in the first place. |
Resources Required
| Rainbow table of password hash chains with the right algorithm used. A password cracking tool that leverages this rainbow table will also be required. Hash(es) of the password is required. |
Indicators
| This is a completely offline attack that an attacker can perform at their leisure after the password hashes are obtained. |
Consequences This table specifies different individual consequences associated with the attack pattern. The Scope identifies the security property that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in their attack. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a pattern will be used to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.| Scope | Impact | Likelihood |
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Confidentiality Access Control Authorization | Gain Privileges | |
Mitigations
| Use salt when computing password hashes. That is, concatenate the salt (random bits) with the original password prior to hashing it. |
Example Instances
| BusyBox 1.1.1 does not use a salt when generating passwords, which makes it easier for local users to guess passwords from a stolen password file using techniques such as rainbow tables. See also: CVE-2006-1058 |
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) | Entry ID | Entry Name |
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| 1110.002 | Brute Force:Password Cracking |
Content History | Submissions |
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| Submission Date | Submitter | Organization |
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| 2014-06-23 (Version 2.6) | CAPEC Content Team | The MITRE Corporation | | | Modifications |
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| Modification Date | Modifier | Organization |
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| 2019-04-04 (Version 3.1) | CAPEC Content Team | The MITRE Corporation | | Updated Related_Weaknesses | | 2020-07-30 (Version 3.3) | CAPEC Content Team | The MITRE Corporation | | Updated Description, Related_Attack_Patterns, Related_Weaknesses, Taxonomy_Mappings | | 2020-12-17 (Version 3.4) | CAPEC Content Team | The MITRE Corporation | | Updated @Abstraction, Related_Attack_Patterns | | 2021-06-24 (Version 3.5) | CAPEC Content Team | The MITRE Corporation | | Updated Related_Weaknesses | | 2022-02-22 (Version 3.7) | CAPEC Content Team | The MITRE Corporation | | Updated Description, Extended_Description |
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