CVE-2020-15387 in Fabric OS
Summary
by MITRE • 06/09/2021
The host SSH servers of Brocade Fabric OS before Brocade Fabric OS v7.4.2h, v8.2.1c, v8.2.2, v9.0.0, and Brocade SANnav before v2.1.1 utilize keys of less than 2048 bits, which may be vulnerable to man-in-the-middle attacks and/or insecure SSH communications.
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Analysis
by VulDB Data Team • 06/12/2021
The vulnerability identified as CVE-2020-15387 affects Brocade Fabric OS and SANnav systems where SSH servers utilize cryptographic keys smaller than 2048 bits. This weakness creates significant security risks for network infrastructure management and monitoring systems that rely on these platforms. The affected versions include Brocade Fabric OS before v7.4.2h, v8.2.1c, v8.2.2, and v9.0.0, along with Brocade SANnav before v2.1.1, representing a substantial portion of the Brocade networking ecosystem. The use of insufficient key lengths directly violates established cryptographic security standards and exposes organizations to serious threats in their storage area network environments.
The technical flaw stems from the implementation of SSH key exchange mechanisms that do not enforce minimum key strength requirements. When SSH servers utilize keys smaller than 2048 bits, they become susceptible to various cryptographic attacks including brute force and mathematical factorization attempts that can compromise the encryption integrity. This vulnerability specifically relates to CWE-326, which addresses the use of weak encryption algorithms and insufficient key sizes in security implementations. The insufficient key length creates a pathway for attackers to potentially intercept and manipulate communications between network administrators and Brocade storage switches, undermining the fundamental security assurances that SSH protocols are designed to provide.
The operational impact of this vulnerability extends beyond simple cryptographic weakness to encompass broader security risks within enterprise storage networks. Organizations using affected Brocade systems face potential man-in-the-middle attacks that could allow unauthorized access to critical network infrastructure, data manipulation, and privilege escalation opportunities. Attackers could exploit this weakness to gain administrative control over storage switches, potentially leading to data breaches, network disruption, and unauthorized access to sensitive corporate information. The vulnerability affects the integrity and confidentiality of management communications, which are essential for maintaining secure storage area network operations and compliance with industry security standards.
Mitigation strategies for CVE-2020-15387 should prioritize immediate firmware upgrades to the patched versions of Brocade Fabric OS and SANnav software. Organizations must also implement network segmentation and monitoring to detect anomalous SSH traffic patterns that could indicate exploitation attempts. Security teams should conduct comprehensive inventory assessments to identify all affected Brocade devices within their network infrastructure and prioritize remediation efforts based on risk exposure levels. The remediation process should include thorough testing of updated firmware in controlled environments before deployment to production systems, ensuring that network operations remain uninterrupted while addressing the cryptographic weaknesses. Additionally, organizations should review their overall security posture and consider implementing additional layers of protection such as network access controls and enhanced monitoring solutions that align with the mitre ATT&CK framework's approach to defending against credential access and privilege escalation techniques.