CVE-2023-28976 Explained : Impact and Mitigation

This CVE-2023-28976 pertains to a vulnerability in Juniper Networks Junos OS on MX Series where a specific traffic rate surpassing the DDoS threshold can lead to an FPC crash. The impact of this vulnerability allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS) by crashing and restarting the ingress PFE upon receiving specific traffic.

Understanding CVE-2023-28976

This section delves into the details of CVE-2023-28976, including the vulnerability description, affected systems and versions, and the exploitation mechanism.

What is CVE-2023-28976?

The vulnerability involves an Improper Check for Unusual or Exceptional Conditions in the packet forwarding engine (pfe) of Juniper Networks Junos OS on MX Series, enabling a network-based attacker to trigger a DoS by causing the ingress PFE to crash and restart with specific high-rate traffic.

The Impact of CVE-2023-28976

The impact of CVE-2023-28976 is the creation of a sustained Denial of Service (DoS) condition due to the ingress PFE crashing and restarting when specific traffic exceeds the respective DDoS protection limit on MX Series.

Technical Details of CVE-2023-28976

This segment focuses on the technical aspects of the vulnerability, including the vulnerability description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability stems from an Uncorrected Check for Unusual or Exceptional Conditions in the packet forwarding engine (pfe) of Juniper Networks Junos OS on MX Series.

Affected Systems and Versions

The vulnerability affects Juniper Networks Junos OS on MX Series, specifically versions prior to 19.1R3-S10, 19.2R3-S7, 19.3R3-S8, 19.4R3-S11, 20.2R3-S5, 20.4R3-S6, 21.1R3-S5, 21.2R3-S4, 21.3R3, 21.4R3, and 22.1R2.

Exploitation Mechanism

An unauthenticated, network-based attacker can exploit the vulnerability by sending specific traffic that exceeds the DDoS protection limit, causing the ingress PFE to crash and restart, leading to a sustained DoS condition.

Mitigation and Prevention

In this section, the mitigation steps and prevention measures for CVE-2023-28976 are outlined.

Immediate Steps to Take

As of now, there are no known workarounds for this vulnerability.

Long-Term Security Practices

Implementing robust network security practices, including access controls and monitoring, can help mitigate the risk of exploitation.

Patching and Updates

Juniper Networks has released updated software versions like 19.4R3-S11, 20.2R3-S5, 20.4R3-S6, 21.1R3-S5, 21.2R3-S4, 21.3R3, 21.4R3, 22.1R2, 22.2R1, and subsequent releases to address this specific issue. It is crucial to promptly apply these patches to secure the network infrastructure against potential attacks.