CWE-732

Incorrect Permission Assignment for Critical Resource
AI Translation Available

The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.

Status
draft
Abstraction
class
Likelihood
high
Not Technology-Specific Cloud Computing

When a resource is given a permission setting that provides access to a wider range of actors than required, it could lead to the exposure of sensitive information, or the modification of that resource by unintended parties. This is especially dangerous when the resource is related to program configuration, execution, or sensitive user data. For example, consider a misconfigured storage account for the cloud that can be read or written by a public or anonymous user.

Common Consequences

confidentiality access control integrity other
Impacts
read application data read files or directories gain privileges or assume identity modify application data other

Detection Methods

automated static analysis automated dynamic analysis manual analysis manual static analysis manual dynamic analysis fuzzing black box automated static analysis - binary or bytecode manual static analysis - binary or bytecode dynamic analysis with automated results interpretation dynamic analysis with manual results interpretation manual static analysis - source code automated static analysis - source code architecture or design review

Potential Mitigations

Phases:
implementation architecture and design operation installation system configuration documentation
Descriptions:
• When using a critical resource such as a configuration file, check to see if the resource has insecure permissions (such as being modifiable by any regular user) [REF-62], and generate an error or even exit the software if there is a possibility that the resource could have been modified by an unauthorized party.
• Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software. OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
• For all configuration files, executables, and libraries, make sure that they are only readable and writable by the software's administrator.
• Do not assume that a system administrator will manually change the configuration to the settings that are recommended in the software's manual.
• When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to disable public access.
• Divide the software into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully defining distinct user groups, privileges, and/or roles. Map these against data, functionality, and the related resources. Then set the permissions accordingly. This will allow you to maintain more fine-grained control over your resources. [REF-207]
• During program startup, explicitly set the default permissions or umask to the most restrictive setting possible. Also set the appropriate permissions during program installation. This will prevent you from inheriting insecure permissions from any user who installs or runs the program.
• Do not suggest insecure configuration changes in documentation, especially if those configurations can extend to resources and other programs that are outside the scope of the application.
• Ensure that the software runs properly under the United States Government Configuration Baseline (USGCB) [REF-199] or an equivalent hardening configuration guide, which many organizations use to limit the attack surface and potential risk of deployed software.