Is CVE-2021-1388 actively exploited?

No active exploitation of CVE-2021-1388 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-1388 be exploited remotely?

Yes. CVE-2021-1388 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-1388?

CVE-2021-1388 has a CVSS score of 10.0 (CRITICAL).

HOME VULNERABILITIESCVE-2021-1388

CRITICAL

CVE-2021-1388

CWE-269Published: February 24, 2021· Updated: Jun 17, 2026

10.0

CVSS v3.1

Official Description

A vulnerability in an API endpoint of Cisco ACI Multi-Site Orchestrator (MSO) installed on the Application Services Engine could allow an unauthenticated, remote attacker to bypass authentication on an affected device. The vulnerability is due to improper token validation on a specific API endpoint. An attacker could exploit this vulnerability by sending a crafted request to the affected API. A successful exploit could allow the attacker to receive a token with administrator-level privileges that could be used to authenticate to the API on affected MSO and managed Cisco Application Policy Infrastructure Controller (APIC) devices.

NVD Source

Technical Analysis

CVE-2021-1388 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.