Is CVE-2021-0248 actively exploited?

No active exploitation of CVE-2021-0248 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-0248 be exploited remotely?

Yes. CVE-2021-0248 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-0248?

CVE-2021-0248 has a CVSS score of 10.0 (CRITICAL).

HOME VULNERABILITIESCVE-2021-0248

CRITICAL

CVE-2021-0248

CWE-798Published: April 22, 2021· Updated: Jun 17, 2026

10.0

CVSS v3.1

Official Description

This issue is not applicable to NFX NextGen Software. On NFX Series devices the use of Hard-coded Credentials in Juniper Networks Junos OS allows an attacker to take over any instance of an NFX deployment. This issue is only exploitable through administrative interfaces. This issue affects: Juniper Networks Junos OS versions prior to 19.1R1 on NFX Series. No other platforms besides NFX Series devices are affected.

NVD Source

Technical Analysis

CVE-2021-0248 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 10.0.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.