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Home > CWE List > CWE-780: Use of RSA Algorithm without OAEP (4.17)  
ID

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.
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+ 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
Section HelpThis 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.
Impact Details

Bypass Protection Mechanism

Scope: Access Control

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
Section Help 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" (View-1000)
Nature Type ID Name
ChildOf Class 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
+ Relevant to the view "Architectural Concepts" (View-1008)
Nature Type ID Name
MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 1013 Encrypt Data
+ Modes Of Introduction
Section HelpThe 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
Medium
+ 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
Method Details

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.)

Effectiveness: High
+ Memberships
Section HelpThis 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.
Nature Type ID Name
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1346 OWASP Top Ten 2021 Category A02:2021 - Cryptographic Failures
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1402 Comprehensive Categorization: Encryption
+ 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
[REF-694] Ronald L. Rivest and Burt Kaliski. "RSA Problem". 2003-12-10.
<http://people.csail.mit.edu/rivest/RivestKaliski-RSAProblem.pdf>.
[REF-695] "Optimal Asymmetric Encryption Padding". Wikipedia. 2009-07-08.
<https://en.wikipedia.org/wiki/Optimal_asymmetric_encryption_padding>. (URL validated: 2023-04-07)
+ Content History
+ Submissions
Submission Date Submitter Organization
2009-07-08
(CWE 1.5, 2009-07-27) 		Fortify Software
Based on information from Fortify Software.
+ Modifications
Modification Date Modifier Organization
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes
2023-04-27 CWE Content Team MITRE
updated Detection_Factors, References, Relationships, Time_of_Introduction
2023-01-31 CWE Content Team MITRE
updated Description
2021-10-28 CWE Content Team MITRE
updated Relationships
2020-02-24 CWE Content Team MITRE
updated Relationships
2017-11-08 CWE Content Team MITRE
updated Modes_of_Introduction, References, Relationships
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
Page Last Updated: April 03, 2025
 

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