CVE-2020-1983

HIGHNVD 7.56.5▼

7.5

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.

CVSS v3: 7.5
EG Score: 6.5(medium)
EPSS: 35.1%
KEV: Not listed

Published

April 22, 2020

Last Modified

November 21, 2024

References (20)

psirt@paloaltonetworkshttp://lists.opensuse.org/opensuse-security-announce/2020-05/msg00022.html
psirt@paloaltonetworkshttp://lists.opensuse.org/opensuse-security-announce/2020-06/msg00001.html
psirt@paloaltonetworkshttps://gitlab.freedesktop.org/slirp/libslirp/-/commit/9ac0371bb8c0a40f5d9f82a1c25129660e81df04
psirt@paloaltonetworkshttps://gitlab.freedesktop.org/slirp/libslirp/-/issues/20
psirt@paloaltonetworkshttps://lists.debian.org/debian-lts-announce/2020/06/msg00032.html
psirt@paloaltonetworkshttps://lists.debian.org/debian-lts-announce/2020/07/msg00020.html
psirt@paloaltonetworkshttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HWFD4MWV3YWIHVHSA2F7FKOLJFL4PHOX/
psirt@paloaltonetworkshttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NKT2MTSINE4NUPG5L6BYH6N23NBNITOL/
psirt@paloaltonetworkshttps://usn.ubuntu.com/4372-1/
psirt@paloaltonetworkshttps://www.debian.org/security/2020/dsa-4665
af854a3a-2127-422b-91ae-364da2661108http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00022.html
af854a3a-2127-422b-91ae-364da2661108http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00001.html
af854a3a-2127-422b-91ae-364da2661108https://gitlab.freedesktop.org/slirp/libslirp/-/commit/9ac0371bb8c0a40f5d9f82a1c25129660e81df04
af854a3a-2127-422b-91ae-364da2661108https://gitlab.freedesktop.org/slirp/libslirp/-/issues/20
af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2020/06/msg00032.html

Patch Availability(9)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
ubuntu	qemu-utils (1:2.5+dfsg-5ubuntu10.44) @ xenial	2026-05-27	ubuntu
ubuntu	qemu-utils (1:6.2+dfsg-2ubuntu6.24) @ jammy	2026-05-27	ubuntu
redhat	qemu-kvm-rhev-10:2.12.0-48.el7_9.2	2021-03-18	redhat
redhat	qemu-kvm-ma-10:2.12.0-48.el7_9.2	2021-02-02	redhat
redhat	virt:rhel-8030020200909014558.30b713e6	2020-11-04	redhat
redhat	virt-devel:8.1-8010120200911011910.5db1954d	2020-10-20	redhat
redhat	qemu-kvm-10:1.5.3-175.el7_9.1	2020-09-30	redhat
redhat	virt-devel:8.2-8020120200707202843.11e3e113	2020-07-28	redhat
redhat	container-tools:rhel8-8020120200601155013.ffd2803a	2020-07-21	redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-416Use After Free

All Vendor Advisories

(10)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 12× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

2026-06-08 14:15 UTCEPSS rescore
2026-06-08 14:15 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-06 13:45 UTCEPSS rescore
2026-06-06 13:45 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 06:08 UTCEPSS rescore
2026-06-05 06:08 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore

Frequently asked(5)

What is CVE-2020-1983?

CVE-2020-1983 is a high vulnerability published on April 22, 2020. A use after free vulnerability in ipreass() in ipinput.c of libslirp 4.2.0 and prior releases allows crafted packets to cause a denial of service.

When was CVE-2020-1983 disclosed?

CVE-2020-1983 was first published in the National Vulnerability Database on April 22, 2020, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2020-1983 actively exploited?

CVE-2020-1983 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 35.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2020-1983?

CVE-2020-1983 has a CVSS v3 base score of 7.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 6.5.

How do I remediate CVE-2020-1983?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-1983, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2020-1983

Published

Last Modified

References (20)

Patch Availability(9)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2020-1983?

Same vendor

Same CWE

CVE-2020-1983

📅 Published

🔄 Last Modified

🔗 References (20)

Patch Availability(9)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2020-1983?

🔗 Related CVEs(same vendor + same CWE)

Same vendor

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References (20)

Frequently asked(5)

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