CVE-2020-5885 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 set up for connection mirroring in a high availability (HA) pair transfer 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-2020-5885 affects F5 BIG-IP systems running specific versions within the 12.1.0 through 15.1.0 release series, representing a critical control plane security weakness that compromises cryptographic object integrity during high availability pair operations. This issue manifests specifically when BIG-IP systems are configured for connection mirroring within a high availability configuration, creating a pathway for sensitive cryptographic materials to be transmitted across insecure network channels.
The technical flaw resides in the improper handling of cryptographic objects during connection mirroring processes, where the system fails to implement adequate encryption for data transmission between HA pair members. This vulnerability stems from a design oversight in the control plane communication protocols that govern how connection state information is synchronized between redundant BIG-IP appliances. The insecure transmission channel exposes cryptographic keys, certificates, and other sensitive security objects that are essential for maintaining the integrity of network connections and security policies.
From an operational impact perspective, this vulnerability creates significant risk for organizations relying on F5 BIG-IP systems for load balancing and application delivery services. Attackers who can intercept traffic on the connection mirroring network segment can potentially extract cryptographic objects that may lead to session hijacking, man-in-the-middle attacks, or the compromise of other security mechanisms dependent on these cryptographic materials. The exposure is particularly concerning because it affects the control plane rather than the data plane, meaning that even if the data plane remains secure, the underlying security infrastructure that governs connection management becomes vulnerable.
The vulnerability aligns with CWE-319 (Cryptographic Issues) and represents a control plane security failure that enables unauthorized access to sensitive cryptographic information through insecure communication channels. This weakness can be leveraged by attackers positioned within the network segment used for connection mirroring, potentially allowing them to escalate privileges or gain deeper access to the system. The attack surface is limited to the specific network segment used for HA communication, but this targeted exposure can still provide attackers with significant leverage for further exploitation.
Organizations should implement immediate mitigations including network segmentation to isolate connection mirroring traffic, deployment of encryption mechanisms for the specific network segment used for HA communication, and thorough network monitoring to detect potential interception attempts. The most effective long-term solution involves upgrading affected BIG-IP systems to versions that properly implement encrypted communication for cryptographic object transfer during connection mirroring operations. Security teams should also conduct comprehensive audits of their HA configurations to identify all systems potentially affected by this vulnerability and ensure proper network access controls are implemented to prevent unauthorized access to the connection mirroring network segments.