Secret leaks often occur when a sensitive piece of authentication data is stored with the source code of an application. Considering the source
code is intended to be deployed across multiple assets, including source code repositories or application hosting servers, the secrets might get
exposed to an unintended audience.
Why is this an issue?
In most cases, trust boundaries are violated when a secret is exposed in a source code repository or an uncontrolled deployment environment.
Unintended people who don’t need to know the secret might get access to it. They might then be able to use it to gain unwanted access to associated
services or resources.
The trust issue can be more or less severe depending on the people’s role and entitlement.
What is the potential impact?
A Google client OAuth secret is a confidential string that is used to authenticate and authorize applications when they interact with Google APIs.
It is a part of the OAuth 2.0 protocol, which allows applications to access user data on their behalf.
The client secret is used in the OAuth flow to verify the identity of the application and ensure that only authorized applications can access user
data. It is typically used in combination with a client ID, which identifies the application itself.
If a Google client OAuth secret leaks to an unintended audience, it can have serious security implications. Attackers who obtain the client secret
can use it to impersonate the application and gain unauthorized access to user data. They can potentially access sensitive information, modify data,
or perform actions on behalf of the user without their consent.
The exact capabilities of the attackers will depend on the authorizations the corresponding application has been granted.
How to fix it
Revoke the secret
Revoke any leaked secrets and remove them from the application source code.
Before revoking the secret, ensure that no other applications or processes are using it. Other usages of the secret will also be impacted when the
secret is revoked.
Analyze recent secret use
When available, analyze authentication logs to identify any unintended or malicious use of the secret since its disclosure date. Doing this will
allow determining if an attacker took advantage of the leaked secret and to what extent.
This operation should be part of a global incident response process.
Google Cloud console provides a Logs Explorer feature that can be used to audit recent access to a cloud infrastructure.
Use a secret vault
A secret vault should be used to generate and store the new secret. This will ensure the secret’s security and prevent any further unexpected
disclosure.
Depending on the development platform and the leaked secret type, multiple solutions are currently available.
Code examples
Noncompliant code example
props.set("client_secret", "TgxYWFmND-1NTYwNTgzMDM3N")
Compliant solution
props.set("client_secret", System.getenv("CLIENT_SECRET"))
Resources
Standards
Documentation
