CWE-515 隐蔽存储通道

Covert Storage Channel

结构: Simple

Abstraction: Base

状态: Incomplete

被利用可能性: High

基本描述

A covert storage channel transfers information through the setting of bits by one program and the reading of those bits by another. What distinguishes this case from that of ordinary operation is that the bits are used to convey encoded information.

扩展描述

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.

相关缺陷

• cwe_Nature: ChildOf cwe_CWE_ID: 514 cwe_View_ID: 1000 cwe_Ordinal: Primary

• cwe_Nature: ChildOf cwe_CWE_ID: 514 cwe_View_ID: 699 cwe_Ordinal: Primary

常见的影响

范围	影响	注释
Confidentiality	Read Application Data	Covert storage channels may provide attackers with important information about the system in question.
['Integrity', 'Confidentiality']	Read Application Data	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.

可能的缓解方案

Implementation

策略:

Ensure that all reserved fields are set to zero before messages are sent and that no unnecessary information is included.

示例代码

例

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.

分类映射

映射的分类名	ImNode ID	Fit	Mapped Node Name
Landwehr			Storage
CLASP			Covert storage channel

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