Skip to main content

Insecure Network Communication

Fixing Certificate Validation​

About Certificate Validation

What is Improper Certificate Validation?​

Improper certificate validation refers to a security vulnerability where a system fails to properly verify the authenticity of a digital certificate presented by a remote party during a communication. This can lead to the acceptance of forged or malicious certificates, allowing attackers to perform various attacks such as man-in-the-middle attacks or impersonation attacks.

Proper certificate validation is crucial for maintaining the security of SSL/TLS encrypted communication and ensuring the confidentiality, integrity, and authenticity of data exchanged over the network.

Check out these videos for a high-level explanation:

  • Weak certificate validation

  • Improper certificate pinning

What is the impact of Improper Certificate Validation?​

Improper certificate validation can lead to a range of security threats, including:

  • Man-in-the-middle attacks: Attackers can intercept communication between two parties and read or modify the data exchanged between them.
  • Data breaches: Attackers can gain unauthorized access to sensitive information or sensitive systems, leading to data breaches.
  • Malware distribution: Attackers can use fake digital certificates to distribute malicious software or infect systems with malware.

Overall, improper certificate validation can undermine the security of encrypted communication and compromise the confidentiality, integrity, and authenticity of data exchanged over the network.

How to prevent Improper Certificate Validation?​

To prevent improper certificate validation, it is important to follow security best practices, such as:

  • Use trusted certificate authorities: Only trust digital certificates issued by well-known and trusted certificate authorities.
  • Verify certificate chains: Verify that the certificate presented by the remote party is valid and issued by a trusted certificate authority. Verify the entire certificate chain, including intermediate certificates.
  • Check certificate revocation status: Check the revocation status of the certificate presented by the remote party to ensure that it has not been revoked.
  • Use certificate pinning: Implement certificate pinning to ensure that the communication only occurs with the exact certificate or certificate authority specified.
  • Keep software up to date: Keep software and security protocols up to date, as new vulnerabilities and security patches are regularly released.

Overall, proper certificate validation is crucial for maintaining the security of encrypted communication, and following these best practices can help prevent improper certificate validation and mitigate related security risks.

References​

Taxonomies​

Explanation & Prevention​

Training​

Option A: Secure the TrustManager​

SSL/TLS certificates can be difficult to manage across environments. Which may result in insecure implementations making it all the way to a production environment. Empty TrustManager implementations are often used to connect to a host that is not signed by a root certificate authority. As a consequence, this is vulnerable to Man-in-the-middle attacks since the client will trust any certificate.

A TrustManager allowing specific certificates (based on a TrustStore for example) should be built. More information about security with HTTPS and SSL can be found here.

Option B: Enforce TLS in WebView​

Insecure WebView implementation, where WebView ignores SSL Certificate errors and accepts any SSL Certificate can lead to Man-in-the-middle attacks. More information can be found here.

Securing TLS configuration​

About Insecure TLS Configuration

What is insecure TLS configuration?​

Insecure TLS (Transport Layer Security) configuration refers to the use of weak or vulnerable cryptographic algorithms or protocols in the configuration of TLS on a system or application.

TLS is used to secure communication channels between clients and servers. Insecure TLS configuration can lead to a range of security vulnerabilities.

Check out these videos for a high-level explanation:

  • Weak Algorithms

  • Weak Cipher Suites

What is the impact of insecure TLS configuration?​

Insecure TLS (Transport Layer Security) configuration can have significant impacts on the security and privacy of communication channels between clients and servers.

Here are some of the potential impacts:

  • Man-in-the-middle (MITM) attacks: Weak or outdated cryptographic algorithms can be exploited by attackers to intercept and modify data in transit between a client and server. This can enable attackers to steal sensitive data or manipulate communication channels to launch other attacks.
  • Information disclosure: Insecure TLS configuration can allow attackers to gain access to sensitive data, such as login credentials or personal information, transmitted between the client and server. This can lead to data breaches or compromise of sensitive information.

How to prevent insecure TLS configuration?​

To prevent insecure TLS (Transport Layer Security) configuration, several measures can be taken, including:

  • Use strong cryptographic algorithms and protocols: Use strong cryptographic algorithms and protocols, such as TLS 1.2 or higher, and disable outdated or weak algorithms, such as SSLv2 and SSLv3. This can help prevent attackers from exploiting vulnerabilities in the encryption and authentication processes.
  • Use appropriate key sizes: Use appropriate key sizes to ensure that the cryptographic keys used in the TLS communication are strong enough to resist attacks. Key sizes of 2048 bits or higher are recommended.
  • Regularly update software and systems: Regularly update software and systems to ensure that the latest security patches are applied and known vulnerabilities are addressed.

References​

Taxonomies​

Explanation & Prevention​

Training​

Option A: Rely on secure TLS versions​

SSL has been considered insecure and it is recommended to switch to TLS v1.3.

Look for patterns like:

  • SSLContext.getInstance("SSL3"): This uses the insecure SSL version 3, use TLSv1.3 instead.
  • new DefaultHttpClient(): This doesn't support TLvS1.2 or above, use a more secure client, as described here
Last updated on by Stefan Streichsbier