CVE-2020-25648

Name: CVE-2020-25648
Creator: NVD / NIST
Published: 2020-10-20T22:15:43.217+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 3.85%

Last modified Jun 17, 2026

CVE-2020-25648 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A flaw was found in the way NSS handled CCS (ChangeCipherSpec) messages in TLS 1.3. This flaw allows a remote attacker to send multiple CCS messages, causing a denial of service for servers compiled with the NSS library. EPSS estimates a 3.85% chance of exploitation in the next 30 days.

Description

A flaw was found in the way NSS handled CCS (ChangeCipherSpec) messages in TLS 1.3. This flaw allows a remote attacker to send multiple CCS messages, causing a denial of service for servers compiled with the NSS library. The highest threat from this vulnerability is to system availability. This flaw affects NSS versions before 3.58.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

3.85%

88.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Mozilla	Network Security Services	< 3.58
Redhat	Enterprise Linux	7.0
Redhat	Enterprise Linux	8.0
Fedoraproject	Fedora	31
Fedoraproject	Fedora	32
Fedoraproject	Fedora	33
Oracle	Communications Offline Mediation Controller	12.0.0.3.0
Oracle	Communications Pricing Design Center	12.0.0.3.0
Oracle	Jd Edwards Enterpriseone Tools	< 9.2.6.0

References

https://bugzilla.redhat.com/show_bug.cgi?id=1887319Issue Tracking, Third Party Advisory
https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.58_release_notesRelease Notes, Vendor Advisory
https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3E
https://lists.debian.org/debian-lts-announce/2023/10/msg00039.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ERA5SVJQXQMDGES7RIT4F4NQVLD35RXN/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HRM53IQCPZT2US3M7JXTP6I6IBA5RGOD/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RPOLN6DJUYQ3QBQEGLZGV73SNIPK7GHV/
https://www.oracle.com//security-alerts/cpujul2021.htmlPatch, Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.htmlNot Applicable, Third Party Advisory
https://www.oracle.com/security-alerts/cpuoct2021.htmlPatch, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1887319Issue Tracking, Third Party Advisory
https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.58_release_notesRelease Notes, Vendor Advisory
https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3E
https://lists.debian.org/debian-lts-announce/2023/10/msg00039.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ERA5SVJQXQMDGES7RIT4F4NQVLD35RXN/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HRM53IQCPZT2US3M7JXTP6I6IBA5RGOD/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RPOLN6DJUYQ3QBQEGLZGV73SNIPK7GHV/
https://www.oracle.com//security-alerts/cpujul2021.htmlPatch, Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.htmlNot Applicable, Third Party Advisory
https://www.oracle.com/security-alerts/cpuoct2021.htmlPatch, Third Party Advisory

Timeline

Published: Oct 20, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-25648?

How severe is CVE-2020-25648?

CVE-2020-25648 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 3.85% probability of exploitation in the next 30 days.

How do I fix CVE-2020-25648?

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-2020-25648?

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

Scan your code now

Source: NVD / NIST