CVE-2022-21170 in i-FILTER
Summary
by MITRE • 03/10/2022
Improper check for certificate revocation in i-FILTER Ver.10.45R01 and earlier, i-FILTER Ver.9.50R10 and earlier, i-FILTER Browser & Cloud MultiAgent for Windows Ver.4.93R04 and earlier, and D-SPA (Ver.3 / Ver.4) using i-FILTER allows a remote unauthenticated attacker to conduct a man-in-the-middle attack and eavesdrop on an encrypted communication.
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Analysis
by VulDB Data Team • 03/13/2022
The vulnerability identified as CVE-2022-21170 represents a critical flaw in the certificate revocation checking mechanism of several i-FILTER products including various versions of i-FILTER server software, browser components, and D-SPA applications. This weakness stems from an inadequate implementation of certificate validation processes that fails to properly verify whether digital certificates have been revoked, creating a significant security gap that can be exploited by remote attackers without authentication requirements. The affected systems include i-FILTER Ver.10.45R01 and earlier versions, i-FILTER Ver.9.50R10 and earlier, i-FILTER Browser & Cloud MultiAgent for Windows Ver.4.93R04 and earlier, as well as D-SPA versions 3 and 4 that utilize the i-FILTER framework. The improper certificate revocation check creates a pathway for attackers to bypass security controls that should prevent communication with compromised or invalid certificates, effectively undermining the fundamental trust model of public key infrastructure.
The technical nature of this vulnerability aligns with CWE-295, which specifically addresses "Improper Certificate Validation" and falls under the broader category of weak cryptographic implementations. This flaw operates at the transport layer security level where SSL/TLS connections are established, allowing attackers to perform man-in-the-middle attacks by presenting certificates that should have been rejected due to revocation status. The vulnerability exploits the trust relationship between clients and servers by failing to consult certificate revocation lists or online certificate status protocols during the certificate validation process. When a certificate is revoked due to compromise, key theft, or other security incidents, the system should reject connections using that certificate, but this implementation flaw prevents such rejection, enabling attackers to intercept and decrypt sensitive communications.
The operational impact of this vulnerability is severe and far-reaching across organizations utilizing these i-FILTER products, as it allows unauthorized parties to conduct passive eavesdropping on encrypted communications without requiring any authentication credentials. This capability enables attackers to access confidential data, credentials, and sensitive information transmitted through the affected systems, potentially leading to data breaches, intellectual property theft, and unauthorized access to corporate networks. The vulnerability affects both the server-side components and client-side browser applications, creating a comprehensive attack surface that can compromise entire communication infrastructures. Organizations relying on these security products for protecting their network traffic and data transmission are particularly vulnerable, as the flaw exists in the core certificate validation logic that should be providing essential security guarantees.
Mitigation strategies for CVE-2022-21170 must prioritize immediate remediation through official vendor patches and updates that address the certificate revocation checking implementation. Organizations should implement network monitoring to detect unusual certificate validation patterns and potential interception attempts. The ATT&CK framework categorizes this vulnerability under T1573.001 for "Encrypted Channel" and T1041 for "Exfiltration Over C2 Channel", indicating the need for defensive measures that monitor for suspicious network traffic patterns and certificate validation failures. Security teams should also consider implementing additional certificate monitoring solutions that can detect when revoked certificates are being presented, and establish procedures for immediate certificate renewal and replacement. Organizations should conduct comprehensive vulnerability assessments to identify all systems running affected i-FILTER versions and prioritize patching efforts based on risk exposure and criticality of affected communications. The remediation process should include thorough testing of patched systems to ensure that certificate validation functions properly without introducing regressions in legitimate network operations.