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?
Azure Subscription Keys are used to authenticate and authorize access to Azure resources and services. These keys are unique identifiers that are
associated with an Azure subscription and are used to control access to resources such as virtual machines, storage accounts, and databases.
Subscription keys are typically used in API requests to Azure services, and they help ensure that only authorized users and applications can access
and modify resources within an Azure subscription.
If an Azure Subscription Key is leaked to an unintended audience, it can pose a significant security risk to the Azure subscription and the
resources it contains. An attacker who gains access to a subscription key can use it to authenticate and access resources within the subscription,
potentially causing data breaches, data loss, or other malicious activities.
Depending on the level of access granted by the subscription key, an attacker could potentially create, modify, or delete resources within the
subscription, or even take control of the entire subscription. This could result in significant financial losses, reputational damage, and legal
liabilities for the organization that owns the subscription.
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.
Microsoft Azure provides an activity log that can be used to audit the access to the API.
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("subscription_key", "efbb1a98f026d061464af685cd16dcd3")
Compliant solution
props.set("subscription_key", System.getenv("SUBSCRIPTION_KEY"))
Resources
Standards
Documentation
