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?
WeChat application keys are used for authentication and authorization purposes when integrating third-party applications with the WeChat
platform.
Below are some real-world scenarios that illustrate some impacts of an attacker exploiting the secret.
Compromise of sensitive personal data
This kind of service is often used to exchange information that could include personal information, chat logs, and other private data that users
have shared on the platform. This is called Personally Identifiable Information.
The leaked app key could provide a gateway for unauthorized individuals to access and misuse this data, compromising the privacy and safety of the
application users.
In many industries and locations, there are legal and compliance requirements to protect sensitive data. If this kind of sensitive personal data
gets leaked, companies face legal consequences, penalties, or violations of privacy laws.
Phishing and spam
An attacker can use this secret to spam users or lure them into links to a malicious domain controlled by the attacker.
Spam can cause users to be exposed to the following:
- Unsolicited, inappropriate content, such as pornographic material
- Fraudulent attempts to trick users into sending information or money
- Abusive or hateful statements
- False advertising or fraudulent claims
Once a user has been phished on a legitimate-seeming third-party website, an attacker can collect the user’s credentials, bypass multi-factor
authentication (MFA), and take over the user’s account on the trusted website.
Malware distribution
Due to this vulnerability, malware can be stored and spread, both to users of the service and to other potential targets.
A malware depends on
the attacker’s intentions, as the following examples show:
- Cryptojacking malware, whose goal is to "mine" cryptocurrencies on the affected computers or servers.
- Spyware that spies out sensitive information from victims.
In the worst case, malware can cause the target systems to be completely compromised and allow attackers to infiltrate the systems.
WeChat exploitation
Furthermore, the leaked app key could enable unauthorized parties to manipulate or disrupt the functionality of the WeChat app. They could tamper
with app settings, inject malicious code, or even take control of the app’s user base. Such actions could result in a loss of user trust, service
disruptions, and reputational damage for both the app developer and the WeChat platform.
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.
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("secret_key", "40b6b70508b47cbfb4ee39feb617a05a")
Compliant solution
props.set("secret_key", System.getenv("SECRET_KEY"))
Resources
Standards
