CVE-2020-5886 in BIG-IP
Summary
by MITRE
On versions 15.0.0-15.1.0.1, 14.1.0-14.1.2.3, 13.1.0-13.1.3.3, and 12.1.0-12.1.5.1, BIG-IP systems setup for connection mirroring in a High Availability (HA) pair transfers sensitive cryptographic objects over an insecure communications channel. This is a control plane issue which is exposed only on the network used for connection mirroring.
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Analysis
by VulDB Data Team • 10/14/2020
The vulnerability identified as CVE-2020-5886 affects F5 BIG-IP systems running specific versions within the 12.1.x, 13.1.x, 14.1.x, and 15.0.x release series. This represents a critical security flaw that compromises the integrity of cryptographic operations within high availability configurations, specifically when connection mirroring is enabled. The issue manifests as an insecure transmission of sensitive cryptographic objects across the control plane network, creating a significant attack surface that adversaries can exploit to compromise the security posture of the affected systems.
The technical implementation flaw resides in how BIG-IP systems handle cryptographic object transmission during connection mirroring operations within HA pairs. When connection mirroring is configured, the system must synchronize connection state information between the primary and secondary devices to maintain service continuity during failover events. However, the vulnerability allows these cryptographic objects to be transmitted over unencrypted channels, making them susceptible to interception and manipulation. This behavior violates fundamental security principles regarding the protection of cryptographic materials and sensitive data during network transmission, as outlined in security standards such as those referenced in CWE-319 - Cryptographic Issues and CWE-295 - Improper Certificate Validation.
The operational impact of this vulnerability extends beyond simple data exposure, as it enables potential attackers to access and manipulate cryptographic keys, certificates, and other sensitive security objects that are critical for maintaining the confidentiality and integrity of network communications. Attackers who gain access to the connection mirroring network segment can intercept these transmissions and potentially decrypt sensitive traffic, forge authentication tokens, or perform man-in-the-middle attacks against the mirrored connections. This vulnerability particularly affects organizations that rely on BIG-IP systems for critical network services and security infrastructure, as it undermines the fundamental security guarantees provided by the system's cryptographic implementations. The control plane nature of this issue means that even if the data plane remains secure, the compromise of cryptographic objects in the control plane can lead to broader system compromise and the potential for lateral movement within the network.
Mitigation strategies for CVE-2020-5886 should focus on immediate network segmentation and encryption enforcement. Organizations must ensure that the connection mirroring network is properly isolated and that all communications between HA pair devices are encrypted using strong cryptographic protocols such as TLS 1.2 or higher. F5 recommends applying the vendor-provided security patches immediately to address the vulnerability, as well as implementing network access controls to restrict unauthorized access to the connection mirroring network segment. Security teams should also conduct thorough network audits to identify all BIG-IP systems running vulnerable versions and ensure that proper encryption is enforced for all control plane communications. The vulnerability aligns with ATT&CK technique T1046 - Network Service Scanning and T1566 - Phishing, as attackers may leverage the exposed cryptographic objects to establish persistence and conduct more sophisticated attacks against the compromised infrastructure. Organizations should also consider implementing network monitoring solutions that can detect anomalous traffic patterns associated with connection mirroring and cryptographic object transmission to provide additional layers of defense against exploitation attempts.