CVE-2021-0290

/// Technical description

Improper Handling of Exceptional Conditions in Ethernet interface frame processing of Juniper Networks Junos OS allows an attacker to send specially crafted frames over the local Ethernet segment, causing the interface to go into a down state, resulting in a Denial of Service (DoS) condition. The interface does not recover on its own and the FPC must be reset manually. Continued receipt and processing of these frames will create a sustained Denial of Service (DoS) condition. This issue is platform-specific and affects the following platforms and line cards: * MPC7E/8E/9E and MPC10E on MX240, MX480, MX960, MX2008, MX2010, and MX2020 * MX204, MX10003, MX10008, MX10016 * EX9200, EX9251 * SRX4600 No other products or platforms are affected by this vulnerability. An indication of this issue occurring can be seen in the system log messages, as shown below: user@host> show log messages | match "Failed to complete DFE tuning" fpc4 smic_phy_dfe_tuning_state: et-4/1/6 - Failed to complete DFE tu

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References