Covert Storage Channel |
| Weakness ID: 515 (Weakness Base) | Status: Incomplete |
DescriptionDescription Summary
Extended Description
Covert storage channels occur when out-of-band data is stored in messages for the purpose of memory reuse. Covert channels are frequently classified as either storage or timing channels. Examples would include using a file intended to hold only audit information to convey user passwords--using the name of a file or perhaps status bits associated with it that can be read by all users to signal the contents of the file. Steganography, concealing information in such a manner that no one but the intended recipient knows of the existence of the message, is a good example of a covert storage channel.
Time of Introduction- Implementation
Common Consequences| Scope | Effect |
|---|---|
Confidentiality | Covert storage channels may provide attackers with important information about the system in question. |
Integrity Confidentiality | If these messages or packets are sent with unnecessary data contained within, it may tip off malicious listeners as to the process that created the message. With this information, attackers may learn any number of things, including the hardware platform, operating system, or algorithms used by the sender. This information can be of significant value to the user in launching further attacks. |
Likelihood of ExploitHigh
Demonstrative ExamplesExample 1
An excellent example of covert storage channels in a well known application is the ICMP error message echoing functionality. Due to ambiguities in the ICMP RFC, many IP implementations use the memory within the packet for storage or calculation. For this reason, certain fields of certain packets -- such as ICMP error packets which echo back parts of received messages -- may contain flaws or extra information which betrays information about the identity of the target operating system. This information is then used to build up evidence to decide the environment of the target. This is the first crucial step in determining if a given system is vulnerable to a particular flaw and what changes must be made to malicious code to mount a successful attack.
Potential MitigationsPhase: Implementation Ensure that all reserved fields are set to zero before messages are sent and that no unnecessary information is included. |
Relationships| Nature | Type | ID | Name | View(s) this relationship pertains to |
|---|---|---|---|---|
| ChildOf |  Weakness Class | 514 | Covert Channel | Development Concepts (primary)699 Research Concepts (primary)1000 |
Taxonomy Mappings| Mapped Taxonomy Name | Node ID | Fit | Mapped Node Name |
|---|---|---|---|
| Landwehr | Storage | ||
| CLASP | Covert storage channel |
Content History| Submissions | ||||
|---|---|---|---|---|
| Submission Date | Submitter | Organization | Source | |
| Landwehr | Externally Mined | |||
| Modifications | ||||
| Modification Date | Modifier | Organization | Source | |
| 2008-07-01 | Eric Dalci | Cigital | External | |
| updated Time of Introduction | ||||
| 2008-09-08 | CWE Content Team | MITRE | Internal | |
| updated Common Consequences, Relationships, Other Notes, Taxonomy Mappings | ||||
| 2008-10-14 | CWE Content Team | MITRE | Internal | |
| updated Description | ||||
| 2009-07-27 | CWE Content Team | MITRE | Internal | |
| updated Common Consequences, Description | ||||
| 2009-10-29 | CWE Content Team | MITRE | Internal | |
| updated Other Notes | ||||
