The product does not encrypt sensitive or critical information before storage or transmission.

What CVEs are caused by CWE-311?

292 recorded CVEs are attributed to CWE-311, including CVE-2023-6339, CVE-2020-35168, CVE-2019-6526.

Is CWE-311 part of the OWASP Top 10?

CWE-311 maps to OWASP Top Ten 2007: Insecure Cryptographic Storage (A8) in the OWASP security taxonomy.

What are the consequences of CWE-311?

Exploiting CWE-311 can lead to: Read Application Data, Modify Application Data.

Is CWE-311 actively exploited?

292 recorded CVEs are caused by CWE-311; none are currently in CISA's KEV catalog of actively exploited flaws.

CWE-311: Missing Encryption of Sensitive Data

Overview

CWE-311 (Missing Encryption of Sensitive Data) is a class-level software weakness catalogued by MITRE in the Common Weakness Enumeration (CWE). It describes a recurring type of mistake that can lead to exploitable security vulnerabilities.

Real-world CVEs

292 recorded CVEs are caused by CWE-311 (Missing Encryption of Sensitive Data). The highest-severity and most recent are shown first. 8 new CWE-311 CVEs have been recorded so far in 2026 (38 in 2025).

Showing 12 of 292 recorded CWE-311 CVEs. Track new ones as they are published and get AI-written analysis and fixes.

Monitor CWE-311 vulnerabilities

Common consequences

What can happen when CWE-311 is exploited.

Read Application Data

Affects: Confidentiality

If the application does not use a secure channel, such as SSL, to exchange sensitive information, it is possible for an attacker with access to the network traffic to sniff packets from the connection and uncover the data. This attack is not technically difficult, but does require physical access to some portion of the network over which the sensitive data travels. This access is usually somewhere near where the user is connected to the network (such as a colleague on the company network) but can be anywhere along the path from the user to the end server.

Modify Application Data

Affects: Confidentiality, Integrity

Omitting the use of encryption in any program which transfers data over a network of any kind should be considered on par with delivering the data sent to each user on the local networks of both the sender and receiver. Worse, this omission allows for the injection of data into a stream of communication between two parties -- with no means for the victims to separate valid data from invalid. In this day of widespread network attacks and password collection sniffers, it is an unnecessary risk to omit encryption from the design of any system which might benefit from it.

How it happens

When it is introduced

Typically introduced during these phases of the software lifecycle.

Architecture and Design

Operation

How to prevent it

Practical mitigations for CWE-311, grouped by where in the lifecycle they apply.

Requirements

Clearly specify which data or resources are valuable enough that they should be protected by encryption. Require that any transmission or storage of this data/resource should use well-vetted encryption algorithms.

Architecture and Design

Ensure that encryption is properly integrated into the system design, including but not necessarily limited to:

Identify the separate needs and contexts for encryption:

Using threat modeling or other techniques, assume that data can be compromised through a separate vulnerability or weakness, and determine where encryption will be most effective. Ensure that data that should be private is not being inadvertently exposed using weaknesses such as insecure permissions (CWE-732). [REF-7]

Architecture and Design

Libraries or Frameworks

When there is a need to store or transmit sensitive data, use strong, up-to-date cryptographic algorithms to encrypt that data. Select a well-vetted algorithm that is currently considered to be strong by experts in the field, and use well-tested implementations. As with all cryptographic mechanisms, the source code should be available for analysis.

For example, US government systems require FIPS 140-2 certification.

Do not develop custom or private cryptographic algorithms. They will likely be exposed to attacks that are well-understood by cryptographers. Reverse engineering techniques are mature. If the algorithm can be compromised if attackers find out how it works, then it is especially weak.

Periodically ensure that the cryptography has not become obsolete. Some older algorithms, once thought to require a billion years of computing time, can now be broken in days or hours. This includes MD4, MD5, SHA1, DES, and other algorithms that were once regarded as strong. [REF-267]

Architecture and Design

Separation of Privilege

Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.

Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

Implementation

Architecture and Design

When using industry-approved techniques, use them correctly. Don't cut corners by skipping resource-intensive steps (CWE-325). These steps are often essential for preventing common attacks.

Implementation

Attack Surface Reduction

Use naming conventions and strong types to make it easier to spot when sensitive data is being used. When creating structures, objects, or other complex entities, separate the sensitive and non-sensitive data as much as possible.

Effectiveness: Defense in Depth — This makes it easier to spot places in the code where data is being used that is unencrypted.

How to detect it

Manual Analysis

The characterizaton of sensitive data often requires domain-specific understanding, so manual methods are useful. However, manual efforts might not achieve desired code coverage within limited time constraints. Black box methods may produce artifacts (e.g. stored data or unencrypted network transfer) that require manual evaluation.

Effectiveness: High

Automated Analysis

Automated measurement of the entropy of an input/output source may indicate the use or lack of encryption, but human analysis is still required to distinguish intentionally-unencrypted data (e.g. metadata) from sensitive data.