CVE-2023-34337 in MegaRAC SPX
Summary
by MITRE • 07/05/2023
AMI SPx contains a vulnerability in the BMC where a user may cause an inadequate encryption strength by hash-based message authentication code (HMAC). A successful exploit of this vulnerability may lead to a loss of confidentiality, integrity, and availability.
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Analysis
by VulDB Data Team • 07/23/2023
The vulnerability identified as CVE-2023-34337 affects AMI SPx systems through a weakness in the Baseboard Management Controller implementation that utilizes hash-based message authentication code mechanisms. This flaw resides within the cryptographic implementation of the BMC firmware, which is responsible for remote system management and monitoring functions. The issue specifically manifests when the system fails to enforce adequate encryption strength during HMAC operations, creating a potential vector for attackers to compromise the security of the managed system.
This cryptographic weakness represents a significant security concern as it directly impacts the integrity and confidentiality of communications between the BMC and management systems. The insufficient encryption strength in HMAC operations allows malicious actors to potentially manipulate authentication tokens, forge messages, or intercept sensitive data transmitted through the BMC interface. The vulnerability stems from improper implementation of cryptographic protocols where the system may accept weak hash functions or insufficient key lengths during HMAC computations, undermining the fundamental security guarantees that these mechanisms are designed to provide.
The operational impact of this vulnerability extends across multiple security domains including confidentiality, integrity, and availability as indicated in the CVE description. Attackers exploiting this weakness could potentially gain unauthorized access to system management interfaces, manipulate critical system parameters, or disrupt normal operational functions through authenticated attacks. The vulnerability's severity is amplified by the BMC's privileged position within the system architecture, as it typically operates with elevated privileges and controls hardware-level functions. This creates a potential attack surface where adversaries could leverage the compromised HMAC implementation to escalate their privileges or compromise the entire system infrastructure.
From a threat modeling perspective, this vulnerability aligns with CWE-327 which addresses the use of weak cryptographic algorithms and CWE-310 which covers cryptographic issues related to key management and implementation. The attack patterns associated with this flaw would likely follow techniques described in the ATT&CK framework under T1078 for valid accounts and T1566 for social engineering, as attackers might attempt to exploit the weak authentication mechanisms to gain persistent access to system management interfaces. The vulnerability creates opportunities for lateral movement within networked environments where BMCs are used for remote management of enterprise infrastructure.
Mitigation strategies should prioritize immediate firmware updates from AMI to address the cryptographic implementation weakness. Organizations should also implement network segmentation to isolate BMC interfaces from general network traffic, employ strong access controls and authentication mechanisms, and monitor for suspicious activities related to BMC communications. Additionally, regular cryptographic assessments should be conducted to ensure that all authentication mechanisms meet current security standards and that no similar weaknesses exist in other components of the system architecture. The remediation process must include thorough testing of updated firmware to ensure that the cryptographic improvements are properly implemented without introducing regressions in system functionality.