CWE-780: Use of RSA Algorithm without OAEP
|
Weakness ID: 780
Vulnerability Mapping:
ALLOWED
This CWE ID may be used to map to real-world vulnerabilities
Abstraction:
Variant
Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.
|
Description
The product uses the RSA algorithm but does not incorporate Optimal Asymmetric Encryption Padding (OAEP), which might weaken the encryption.
Extended Description
Padding schemes are often used with cryptographic algorithms to make the plaintext less predictable and complicate attack efforts. The OAEP scheme is often used with RSA to nullify the impact of predictable common text.
Common Consequences
 This table specifies different individual consequences
associated with the weakness. The Scope identifies the application security area that is
violated, while the Impact describes the negative technical impact that arises if an
adversary succeeds in exploiting this weakness. 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 weakness will be
exploited to achieve a certain impact, but a low likelihood that it will be exploited to
achieve a different impact.
| Scope |
Impact |
Likelihood |
| Access Control |
Technical Impact: Bypass Protection Mechanism
Without OAEP in RSA encryption, it will take less work for an attacker to decrypt the data or to infer patterns from the ciphertext.
|
|
Relationships
This table shows the weaknesses and high level categories that are related to this
weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to
similar items that may exist at higher and lower levels of abstraction. In addition,
relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user
may want to explore.
Relevant to the view "Research Concepts" (CWE-1000)
| Nature |
Type |
ID |
Name |
| ChildOf |
Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.
|
327
|
Use of a Broken or Risky Cryptographic Algorithm
|
This table shows the weaknesses and high level categories that are related to this
weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to
similar items that may exist at higher and lower levels of abstraction. In addition,
relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user
may want to explore.
Relevant to the view "Architectural Concepts" (CWE-1008)
| Nature |
Type |
ID |
Name |
| MemberOf |
Category - a CWE entry that contains a set of other entries that share a common characteristic.
|
1013
|
Encrypt Data
|
Modes
Of Introduction
The different Modes of Introduction provide information
about how and when this
weakness may be introduced. The Phase identifies a point in the life cycle at which
introduction
may occur, while the Note provides a typical scenario related to introduction during the
given
phase.
| Phase |
Note |
| Implementation |
REALIZATION: This weakness is caused during implementation of an architectural security tactic. |
Likelihood Of Exploit
Demonstrative Examples
Example 1
The example below attempts to build an RSA cipher.
(bad code)
Example Language: Java
public Cipher getRSACipher() { Cipher rsa = null; try { rsa = javax.crypto.Cipher.getInstance("RSA/NONE/NoPadding"); } catch (java.security.NoSuchAlgorithmException e) { log("this should never happen", e); } catch (javax.crypto.NoSuchPaddingException e) { log("this should never happen", e); } return rsa; }
While the previous code successfully creates an RSA cipher, the cipher does not use padding. The following code creates an RSA cipher using OAEP.
(good code)
Example Language: Java
public Cipher getRSACipher() { Cipher rsa = null; try { rsa = javax.crypto.Cipher.getInstance("RSA/ECB/OAEPWithMD5AndMGF1Padding"); } catch (java.security.NoSuchAlgorithmException e) { log("this should never happen", e); } catch (javax.crypto.NoSuchPaddingException e) { log("this should never happen", e); } return rsa; }
Detection
Methods
|
Automated Static Analysis
Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
|
Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that
reference this weakness as a member. This information is often useful in understanding where a
weakness fits within the context of external information sources.
Vulnerability Mapping Notes
|
Usage:
ALLOWED
(this CWE ID may be used to map to real-world vulnerabilities)
|
|
Reason:
Acceptable-Use
|
|
Rationale:
This CWE entry is at the Variant level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
|
|
Comments: Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.
|
Notes
Maintenance
This entry could probably have a new parent related to improper padding, however the role of padding in cryptographic algorithms can vary, such as hiding the length of the plaintext and providing additional random bits for the cipher. In general, cryptographic problems in CWE are not well organized and further research is needed.
References
More information is available — Please edit the custom filter or select a different filter.
|
