Exploring the Security Issues of Trusted CA Certificate Management

Public Key Infrastructure (PKI) is widely used in security protocols, and the root certification authority (CA) plays a role as the trust anchor of PKI. However, as researches show, not all root CAs are trustworthy and malicious CAs might issue fraudulent certificates, which can cause Man-in-the-Middle attacks and eavesdropping attacks. Besides, massive CAs and CA certificates make it hard for users to manage the CA certificates by themselves. Though PKI applications generally provide the implementation of trusted CA certificate management (called CA manager in this paper) to store, manage, and verify CA certificates, security incidents still exist, and a malicious CA certificate can damage the entire security. This work explores the security issues of CA managers for three popular operating systems and eight applications installed on them. We make a systematic analysis of the CA managers, such as the modification of the certificate trust list, the source of trust, and the security check of the CA certificates, and propose the functionalities that a CA manager should have. Our work shows that all CA managers we analyzed have security issues, e.g., silent addition of CA certificates, inefficient validation on CA certificates, which will result in insecure CA certificates being falsely trusted. We also make some suggestions on the security enhancement for CA managers.