CVE-2020-13111

Name: CVE-2020-13111
Creator: NVD / NIST
Published: 2020-05-16T15:15:11.377+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.44%

Last modified Jun 17, 2026

CVE-2020-13111 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. NaviServer 4.99.4 to 4.99.19 allows denial of service due to the nsd/driver.c ChunkedDecode function not properly validating the length of a chunk. A remote attacker can craft a chunked-transfer request that will result in a negative value being passed to memmove via the size parameter, causing the process to crash.. EPSS estimates a 1.44% chance of exploitation in the next 30 days.

Description

NaviServer 4.99.4 to 4.99.19 allows denial of service due to the nsd/driver.c ChunkedDecode function not properly validating the length of a chunk. A remote attacker can craft a chunked-transfer request that will result in a negative value being passed to memmove via the size parameter, causing the process to crash.

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

1.44%

69.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Naviserver Project	Naviserver	>= 4.99.4, <= 4.99.19

References

https://bitbucket.org/naviserver/naviserver/commits/a5c3079f1d8996d5f34c9384a440acf3519ca3bbPatch, Third Party Advisory
https://sourceforge.net/p/naviserver/bugs/89/Permissions Required, Third Party Advisory
https://bitbucket.org/naviserver/naviserver/commits/a5c3079f1d8996d5f34c9384a440acf3519ca3bbPatch, Third Party Advisory
https://sourceforge.net/p/naviserver/bugs/89/Permissions Required, Third Party Advisory

Timeline

Published: May 16, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-13111?

How severe is CVE-2020-13111?

CVE-2020-13111 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.44% probability of exploitation in the next 30 days.

How do I fix CVE-2020-13111?

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-2020-13111?

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

Scan your code now

Source: NVD / NIST