CVE-2021-4076 in tang
Summary
by MITRE • 03/03/2022
A flaw exists in tang, a network-based cryptographic binding server, which could result in leak of private keys.
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Analysis
by VulDB Data Team • 03/06/2022
The vulnerability identified as CVE-2021-4076 resides within tang, a network-based cryptographic binding server that facilitates secure key management and authentication services. This flaw represents a critical security weakness that directly impacts the confidentiality and integrity of cryptographic operations within the system. The tang server operates as a critical component in cryptographic binding scenarios, where it manages the establishment of secure connections between clients and cryptographic keys, making it a prime target for attackers seeking to compromise sensitive cryptographic material.
The technical flaw manifests as a vulnerability that allows for the potential leakage of private keys through improper handling of cryptographic operations within the tang server implementation. This issue stems from inadequate protection mechanisms that fail to properly isolate and secure private key material during network-based cryptographic binding processes. The vulnerability likely involves improper memory management, insufficient access controls, or flawed cryptographic protocol implementations that expose private key components to unauthorized access or extraction. Such weaknesses create an attack surface where adversaries can potentially intercept or retrieve private keys that should remain securely isolated within the server environment.
The operational impact of CVE-2021-4076 extends beyond simple data exposure, fundamentally undermining the security posture of systems relying on tang for cryptographic binding services. When private keys are leaked, the entire cryptographic infrastructure built upon these keys becomes compromised, potentially affecting thousands of connected systems that depend on the integrity of the tang server's key management capabilities. This vulnerability directly violates fundamental security principles outlined in the CIA triad, specifically compromising confidentiality and integrity of cryptographic assets. The implications are particularly severe for environments where tang serves as a central cryptographic authority, as the compromise of private keys can lead to complete credential theft, unauthorized access to encrypted data, and potential man-in-the-middle attacks against legitimate users.
Security professionals should prioritize immediate assessment of systems running tang servers to determine vulnerability status and implement appropriate mitigations. The flaw aligns with CWE-310 (Cryptographic Issues) and potentially CWE-255 (Credentials Management Issues) within the CWE classification system, highlighting the fundamental cryptographic weakness in how the server handles private key material. From an ATT&CK framework perspective, this vulnerability maps to techniques involving credential access and privilege escalation, as adversaries could leverage the leaked private keys to gain elevated access to protected systems. Organizations should implement network segmentation to isolate tang servers, deploy comprehensive monitoring solutions to detect unauthorized access attempts, and ensure immediate patching of affected systems. Additionally, cryptographic key rotation procedures should be implemented immediately, and system administrators should conduct thorough security audits to identify any potential compromise of cryptographic assets that may have occurred due to this vulnerability.