CVE-2021-0281 Explained : Impact and Mitigation

Juniper Networks Junos OS devices configured with BGP origin validation using Resource Public Key Infrastructure (RPKI) are vulnerable to a Denial of Service (DoS) attack. An attacker can trigger a crash in the routing process daemon (RPD) by sending a specific packet from the RPKI cache server, resulting in service disruption. This vulnerability affects multiple versions of Junos OS and Junos OS Evolved.

Understanding CVE-2021-0281

This CVE impacts Juniper Networks Junos OS and Junos OS Evolved installations when BGP Origin Validation is configured with RPKI. The vulnerability can be exploited to crash the RPD, causing a DoS condition.

What is CVE-2021-0281?

The vulnerability in CVE-2021-0281 allows an attacker to crash the routing process daemon (RPD) on Juniper Networks Junos OS devices by sending a specific packet from the RPKI cache server, creating a Denial of Service (DoS) situation.

The Impact of CVE-2021-0281

This vulnerability can lead to service disruption and a sustained DoS condition on affected Junos OS and Junos OS Evolved versions. However, there have been no reported cases of malicious exploitation as confirmed by Juniper SIRT.

Technical Details of CVE-2021-0281

The vulnerability is rated as medium severity with a CVSS base score of 5.9. It has a high attack complexity and can be exploited over a network. The availability impact is high, with no impact on confidentiality or integrity, and no user interaction or privileges required for an attack.

Vulnerability Description

Juniper Networks Junos OS devices are susceptible to crashing the RPD due to a flaw in handling specific packets from the RPKI cache server while using BGP origin validation with RPKI.

Affected Systems and Versions

Various versions of Junos OS and Junos OS Evolved are affected by this vulnerability, ranging from 17.3 to 20.4 for Junos OS and up to 20.4R2-S2-EVO for Junos OS Evolved.

Exploitation Mechanism

The vulnerability can be exploited by sending a crafted packet from the RPKI cache server, triggering a crash in the RPD and leading to a DoS condition.

Mitigation and Prevention

It is crucial to apply the provided software updates to address CVE-2021-0281 and prevent potential exploitation.

Immediate Steps to Take

Update affected Junos OS and Junos OS Evolved installations to the patched versions mentioned in the solution section.

Long-Term Security Practices

Ensure timely updates and patches for all Juniper Networks products to mitigate known vulnerabilities and enhance overall security posture.

Patching and Updates

Juniper Networks has released software updates for Junos OS and Junos OS Evolved to address CVE-2021-0281. Ensure your devices are running the fixed versions to prevent exploitation.