CVE-2020-11939

Name: CVE-2020-11939
Creator: NVD / NIST
Published: 2020-04-23T15:15:14.093+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 3.30%

Last modified Jun 17, 2026

CVE-2020-11939 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. In nDPI through 3.2 Stable, the SSH protocol dissector has multiple KEXINIT integer overflows that result in a controlled remote heap overflow in concat_hash_string in ssh.c. Due to the granular nature of the overflow primitive and the ability to control both the contents and layout of the nDPI library's heap memory through remote input, this vulnerability may be abused to achieve full Remote Code Execution against any network inspection stack that is linked against nDPI and uses it to perform network traffic analysis.. EPSS estimates a 3.30% chance of exploitation in the next 30 days.

Description

In nDPI through 3.2 Stable, the SSH protocol dissector has multiple KEXINIT integer overflows that result in a controlled remote heap overflow in concat_hash_string in ssh.c. Due to the granular nature of the overflow primitive and the ability to control both the contents and layout of the nDPI library's heap memory through remote input, this vulnerability may be abused to achieve full Remote Code Execution against any network inspection stack that is linked against nDPI and uses it to perform network traffic analysis.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

3.30%

87.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Ntop	Ndpi	<= 3.2

References

https://github.com/ntop/nDPI/commit/7ce478a58b4dd29a8d1e6f4e9df2f778613d9202Patch, Third Party Advisory
https://securitylab.github.com/advisories/GHSL-2020-051_052-ntop-ndpiExploit, Third Party Advisory
https://github.com/ntop/nDPI/commit/7ce478a58b4dd29a8d1e6f4e9df2f778613d9202Patch, Third Party Advisory
https://securitylab.github.com/advisories/GHSL-2020-051_052-ntop-ndpiExploit, Third Party Advisory

Timeline

Published: Apr 23, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-11939?

How severe is CVE-2020-11939?

CVE-2020-11939 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 3.30% probability of exploitation in the next 30 days.

How do I fix CVE-2020-11939?

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-2020-11939?

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

Scan your code now

Source: NVD / NIST