CVE-2021-31798 in Credential Provider
Summary
by MITRE • 09/02/2021
The effective key space used to encrypt the cache in CyberArk Credential Provider prior to 12.1 has low entropy, and under certain conditions a local malicious user can obtain the plaintext of cache files.
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Analysis
by VulDB Data Team • 09/05/2021
The vulnerability identified as CVE-2021-31798 affects CyberArk Credential Provider versions prior to 12.1, representing a significant cryptographic weakness that undermines the security of cached credentials. This issue stems from insufficient entropy in the key derivation process, creating predictable encryption keys that compromise the confidentiality of stored sensitive information. The vulnerability specifically targets the cache encryption mechanism that CyberArk employs to protect credential data, making it susceptible to exploitation by local attackers who possess malicious intent.
The technical flaw manifests in the inadequate entropy of the effective key space used for cache encryption, which violates fundamental cryptographic principles outlined in standards such as NIST SP 800-131A and CWE-327. The low entropy encryption keys create a situation where attackers can potentially recover plaintext cache contents through brute force or statistical analysis attacks, particularly when the system operates under predictable conditions. This weakness directly impacts the confidentiality controls that CyberArk implements to protect privileged credentials and access tokens stored in memory.
From an operational perspective, this vulnerability creates a serious risk for organizations relying on CyberArk Credential Provider for credential management, as local malicious users can exploit the weak encryption to gain access to sensitive credential data without requiring additional authentication or network-based attacks. The impact extends beyond simple credential theft to potentially enable lateral movement within networks, privilege escalation, and unauthorized access to critical systems. Attackers could leverage this weakness to obtain access to databases, applications, and network resources that require authenticated access, effectively bypassing the security controls that the credential provider is designed to enforce.
The attack surface for this vulnerability is primarily limited to local system access, aligning with ATT&CK technique T1059.001 for command and scripting interpreter and potentially T1566.001 for credential access through the exploitation of weak encryption. Organizations should implement immediate mitigations including upgrading to CyberArk Credential Provider version 12.1 or later, which addresses the entropy issues in the key derivation process. Additional defensive measures include monitoring for unauthorized local access attempts, implementing strict access controls on systems running the credential provider, and conducting regular security assessments to identify potential exploitation vectors. The vulnerability demonstrates the critical importance of proper cryptographic implementation and the necessity of adhering to established security standards to prevent predictable key generation that undermines the fundamental security properties of encryption mechanisms.