CVE-2021-3523

Name: CVE-2021-3523
Creator: NVD / NIST
Published: 2022-04-27T21:15:08.287+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.79%

Last modified Jun 17, 2026

CVE-2021-3523 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A flaw was found in 3Scale APICast in versions prior to 2.11.0, where it incorrectly identified connections for reuse. This flaw allows an attacker to bypass security restrictions for an API request when hosting multiple APIs on the same IP address.. EPSS estimates a 0.79% chance of exploitation in the next 30 days.

Description

A flaw was found in 3Scale APICast in versions prior to 2.11.0, where it incorrectly identified connections for reuse. This flaw allows an attacker to bypass security restrictions for an API request when hosting multiple APIs on the same IP address.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability

0.79%

51.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Redhat	Apicast	< 2.11.0

References

https://bugzilla.redhat.com/show_bug.cgi?id=1954805Issue Tracking, Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1954805Issue Tracking, Vendor Advisory

Timeline

Published: Apr 27, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3523?

How severe is CVE-2021-3523?

CVE-2021-3523 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.79% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3523?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-3523?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST