CVE-2021-25763

Name: CVE-2021-25763
Creator: NVD / NIST
Published: 2021-02-03T16:15:14.773+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 0.54%

Last modified Jun 17, 2026

CVE-2021-25763 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. In JetBrains Ktor before 1.4.2, weak cipher suites were enabled by default.. EPSS estimates a 0.54% chance of exploitation in the next 30 days.

Description

In JetBrains Ktor before 1.4.2, weak cipher suites were enabled by default.

Metrics

CVSS 3.1

5.3/10

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

EPSS Probability

0.54%

41.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-327

Affected Software

Vendor	Product	Versions
Jetbrains	Ktor	< 1.4.2

References

https://blog.jetbrains.comProduct
https://blog.jetbrains.com/blog/2021/02/03/jetbrains-security-bulletin-q4-2020/Vendor Advisory
https://blog.jetbrains.comProduct
https://blog.jetbrains.com/blog/2021/02/03/jetbrains-security-bulletin-q4-2020/Vendor Advisory

Timeline

Published: Feb 3, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-25763?

In JetBrains Ktor before 1.4.2, weak cipher suites were enabled by default.

How severe is CVE-2021-25763?

CVE-2021-25763 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.54% probability of exploitation in the next 30 days.

How do I fix CVE-2021-25763?

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-2021-25763?

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

Scan your code now

Source: NVD / NIST