CWE-526: Cleartext Storage of Sensitive Information in an Environment Variable
The product uses an environment variable to store unencrypted sensitive information.
How it's found
Cleartext Storage of Sensitive Information in an Environment Variable is a specific, narrowly defined instance of a broader pattern. Testers confirm it with targeted code review and a proof-of-concept input that exercises the exact code path this weakness describes.
Information stored in an environment variable can be accessible by other processes with the execution context, including child processes that dependencies are executed in, or serverless functions in cloud environments. An environment variable's contents can also be inserted into messages, headers, log files, or other outputs. Often these other dependencies have no need to use the environment variable in question. A weakness that discloses environment variables could expose this information.
Consequences
- Read Application Data
Mitigations
- Architecture and Design: Encrypt information stored in the environment variable to protect it from being exposed to an unauthorized user. If encryption is not feasible or is considered too expensive for the business use of the application, then consider using a properly protected configuration file instead of an environment variable. It should be understood that unencrypted information in a config file is also not guaranteed to be protected, but it is still a better choice, because it reduces attack surface related to weaknesses such as CWE-214. In some settings, vaults might be a feasible option for safer data transfer. Users should be notified of the business choice made to not protect the sensitive information through encryption.
- Implementation: If the environment variable is not necessary for the desired behavior, then remove it entirely, or clear it to an empty value.
Where this fits in a TurboPentest engagement
This weakness is not covered by the automated black-box pentest. IntegSec pentesters cover it in a manual engagement.
Frequently asked questions
What is CWE-526?
The product uses an environment variable to store unencrypted sensitive information.
How do you find Cleartext Storage of Sensitive Information in an Environment Variable?
Cleartext Storage of Sensitive Information in an Environment Variable is a specific, narrowly defined instance of a broader pattern. Testers confirm it with targeted code review and a proof-of-concept input that exercises the exact code path this weakness describes.
What is the impact of CWE-526?
Read Application Data
Does TurboPentest test for Cleartext Storage of Sensitive Information in an Environment Variable?
This weakness is not covered by the automated black-box pentest. IntegSec pentesters cover it in a manual engagement.
Related CWEs
Written and reviewed by
Michel Chamberland - Founder & CEO, IntegSec
CISSP, OSCP, OSCE, CEH, GIAC, CCSK · 20+ years in offensive security
Michel has spent 20+ years on offensive security teams including IBM X-Force Red and Trustwave SpiderLabs, leading penetration tests, red team engagements, and breach response for Fortune 500 customers. He is the founder of IntegSec and the architect of TurboPentest.
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