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?
Passwords in PostgreSQL are used to authenticate users against the database engine. They are associated with user accounts that are granted
specific permissions over the database and its hosted data.
If a PostgreSQL password leaks to an unintended audience, it can have serious consequences for the security of your database, the data stored
within it, and the applications that rely on it.
Compromise of sensitive data
If the affected service is used to store or process personally identifiable information or other sensitive data, attackers knowing an
authentication secret could be able to access it. Depending on the type of data that is compromised, it could lead to privacy violations, identity
theft, financial loss, or other negative outcomes.
In most cases, a company suffering a sensitive data compromise will face a reputational loss when the security issue is publicly disclosed.
Security downgrade
Applications relying on a PostgreSQL database instance can suffer a security downgrade if an access password is leaked to attackers. Depending on
the purposes the application uses the database for, consequences can range from low-severity issues, like defacement, to complete compromise.
For example, if the PostgreSQL instance is used as part of the authentication process of an application, attackers with access to the database will
likely be able to bypass this security mechanism.
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.
By default, no connection information is logged by PostgreSQL server. The log_connections parameter must be set to true
in the server configuration for this to happen.
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.
Never hard-code secrets, not even the default values
It is important that you do not hard-code secrets, even default values.
First, hard-coded default secrets are often short and can be easily compromised even by attackers who do not have access to the code base.
Second, hard-coded default secrets can cause problems if they need to be changed or replaced.
And most importantly, there is always the possibility to accidentally set default secrets for production services, which can lead to security
vulnerabilities and make production insecure by default.
To minimize these risks, it is recommended to apply the above strategies, even for the default settings.
Code examples
Noncompliant code example
uri = "postgres://foouser:foopass@example.com/testdb"
Compliant solution
import os
user = os.environ["PG_USER"]
password = os.environ["PG_PASSWORD"]
uri = f"postgres://{user}:{password}@example.com/testdb"
Resources
Standards
Documentation
