CVE-2020-1983

Name: CVE-2020-1983
Creator: NVD / NIST
Published: 2020-04-22T20:15:11.48+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 2.29%

Last modified Jun 17, 2026

CVE-2020-1983 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. A use after free vulnerability in ip_reass() in ip_input.c of libslirp 4.2.0 and prior releases allows crafted packets to cause a denial of service.. EPSS estimates a 2.29% chance of exploitation in the next 30 days.

Description

A use after free vulnerability in ip_reass() in ip_input.c of libslirp 4.2.0 and prior releases allows crafted packets to cause a denial of service.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

2.29%

81.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Libslirp Project	Libslirp	<= 4.2.0
Fedoraproject	Fedora	31
Fedoraproject	Fedora	32
Debian	Debian Linux	8.0
Debian	Debian Linux	9.0
Opensuse	Leap	15.1
Canonical	Ubuntu Linux	16.04
Canonical	Ubuntu Linux	18.04
Canonical	Ubuntu Linux	19.10
Canonical	Ubuntu Linux	20.04

References

http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00022.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00001.htmlMailing List, Third Party Advisory
https://gitlab.freedesktop.org/slirp/libslirp/-/commit/9ac0371bb8c0a40f5d9f82a1c25129660e81df04Patch, Third Party Advisory
https://gitlab.freedesktop.org/slirp/libslirp/-/issues/20Exploit, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/06/msg00032.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00020.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HWFD4MWV3YWIHVHSA2F7FKOLJFL4PHOX/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NKT2MTSINE4NUPG5L6BYH6N23NBNITOL/
https://usn.ubuntu.com/4372-1/Third Party Advisory
https://www.debian.org/security/2020/dsa-4665Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00022.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00001.htmlMailing List, Third Party Advisory
https://gitlab.freedesktop.org/slirp/libslirp/-/commit/9ac0371bb8c0a40f5d9f82a1c25129660e81df04Patch, Third Party Advisory
https://gitlab.freedesktop.org/slirp/libslirp/-/issues/20Exploit, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/06/msg00032.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00020.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HWFD4MWV3YWIHVHSA2F7FKOLJFL4PHOX/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NKT2MTSINE4NUPG5L6BYH6N23NBNITOL/
https://usn.ubuntu.com/4372-1/Third Party Advisory
https://www.debian.org/security/2020/dsa-4665Third Party Advisory

Timeline

Published: Apr 22, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-1983?

A use after free vulnerability in ip_reass() in ip_input.c of libslirp 4.2.0 and prior releases allows crafted packets to cause a denial of service.

How severe is CVE-2020-1983?

CVE-2020-1983 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 2.29% probability of exploitation in the next 30 days.

How do I fix CVE-2020-1983?

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-2020-1983?

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

Scan your code now

Source: NVD / NIST