CVE-2023-23632 in Privileged Remote Access
Summary
by MITRE • 10/25/2023
BeyondTrust Privileged Remote Access (PRA) versions 22.2.x to 22.4.x are vulnerable to a local authentication bypass. Attackers can exploit a flawed secret verification process in the BYOT shell jump sessions, allowing unauthorized access to jump items by guessing only the first character of the secret.
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Analysis
by VulDB Data Team • 10/31/2023
The vulnerability identified as CVE-2023-23632 affects BeyondTrust Privileged Remote Access PRA versions 22.2.x through 22.4.x, presenting a critical local authentication bypass flaw that significantly compromises privileged access security. This vulnerability specifically targets the BYOT shell jump sessions functionality within the privileged access management solution, creating a dangerous weakness in the authentication process that can be exploited by malicious actors. The flaw stems from an inadequate secret verification mechanism that fails to properly validate authentication credentials, particularly in scenarios involving jump items that require privileged access to remote systems. Organizations relying on BeyondTrust PRA for managing privileged accounts face substantial risk as this vulnerability undermines the fundamental security controls designed to protect sensitive environments. The authentication bypass capability represents a serious regression in security posture, as it allows attackers to gain unauthorized access to privileged resources without proper credential validation.
The technical implementation of this vulnerability lies in the flawed secret verification process that governs how authentication credentials are validated during BYOT shell jump sessions. When users attempt to access jump items through the privileged access management system, the authentication mechanism fails to properly verify the complete secret value, instead accepting incomplete verification that only requires guessing the first character of the secret. This weakness directly maps to CWE-287, which addresses improper authentication issues in software systems, specifically highlighting the failure to properly validate authentication credentials. The vulnerability creates a scenario where an attacker with minimal information can potentially gain access to privileged resources by simply guessing the initial character of the authentication secret, dramatically reducing the effective entropy of the authentication mechanism. The implementation flaw likely involves insufficient input validation or premature acceptance of partial credential verification, allowing the system to proceed with access granting despite incomplete authentication.
The operational impact of this vulnerability extends beyond simple unauthorized access, creating potential for significant security breaches within organizations that depend on BeyondTrust PRA for privileged access management. Attackers exploiting this vulnerability can bypass the intended authentication controls and gain access to jump items that typically require proper privileged credentials, potentially leading to lateral movement within networks and access to sensitive systems. The risk is particularly elevated in environments where privileged accounts control critical infrastructure, databases, and sensitive applications, as the vulnerability enables attackers to escalate their privileges without detection. This authentication bypass can facilitate advanced persistent threats where adversaries use the compromised privileged access to maintain long-term presence within networks, conduct data exfiltration, or manipulate critical systems. The vulnerability's impact is amplified by the fact that it operates at the local authentication level, meaning it can be exploited without requiring network-level access or complex attack vectors.
Organizations affected by CVE-2023-23632 should implement immediate mitigations including upgrading to BeyondTrust PRA versions that address this authentication bypass vulnerability, as well as implementing additional access controls and monitoring measures. The recommended approach involves applying the vendor-provided patches or updates that correct the flawed secret verification process, ensuring that all authentication credentials are properly validated before granting access to jump items. Security teams should also implement enhanced monitoring of privileged access activities, particularly around BYOT shell jump sessions, to detect anomalous access patterns that might indicate exploitation attempts. Additional defensive measures include implementing multi-factor authentication for privileged access, reducing the attack surface by limiting jump item access, and conducting thorough security assessments of privileged access workflows. The vulnerability demonstrates the critical importance of proper authentication mechanism design and validation, aligning with ATT&CK technique T1078 which covers valid accounts and legitimate credential use for persistence and privilege escalation. Organizations should also consider implementing privileged access management controls that enforce strict verification processes and maintain audit trails for all privileged access activities to detect and respond to potential exploitation attempts.