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.
CVE-2020-1983
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 2.4% (83rd percentile of EPSS-scored CVEs). GitHub Security Advisory enrichment pending alignment with NVD CVSS.
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5HIGHmedium confidence
- EG Risk
- 39EG Risk 39/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation2% × 40%Automatability30% × 15%CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 2.4%
- EPSS %ILE
- 83rd
- KEV
- Not listed
CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
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
Vendor Advisories for CVE-2020-1983(4)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2020:4676Red Hat Product SecurityMedium
Red Hat Security Advisory: virt:rhel and virt-devel:rhel security, bug fix, and enhancement update
- RHSA-2020:4290Red Hat Product SecurityHigh
Red Hat Security Advisory: virt:8.1 and virt-devel:8.1 security update
- RHSA-2020:4079Red Hat Product SecurityHigh
Red Hat Security Advisory: qemu-kvm security update
- RHBA-2020:3172Red Hat Product SecurityMedium
Red Hat Bug Fix Advisory: Advanced Virtualization bug fix and enhancement update
Patch Availability(9)
| Vendor / Ecosystem | Fix (by version range) / 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.
Affected Packages
(15 across 7 ecosystems)
Debian:11(3)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libslirp | — |
| — |
| qemu | — |
| — |
| slirp4netns | — |
| — |
Debian:12(3)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libslirp | — |
| — |
| qemu | — |
| — |
| slirp4netns | — |
| — |
Debian:13(3)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libslirp | — |
| — |
| qemu | — |
| — |
| slirp4netns | — |
| — |
Debian:14(3)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libslirp | — |
| — |
| qemu | — |
| — |
| slirp4netns | — |
| — |
Debian:10(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| qemu | 1:3.1+dfsg-8, 1:3.1+dfsg-8+deb10u2, 1:3.1+dfsg-8+deb10u3, 1:3.1+dfsg-8+deb10u4, 1:3.1+dfsg-8~deb10u1 |
| — |
Debian:8(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| qemu | 1:2.1+dfsg-11 ... 1:2.1+dfsg-12~bpo70+1 (20 versions) |
| — |
Debian:9(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| qemu | 1:2.8+dfsg-6 ... 1:2.8+dfsg-6+deb9u9 (10 versions) |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(6)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
- Red HatRHSA-2020:3053MODERATE2020-04-02
RHSA-2020:3053 — Moderate
- Red HatRHSA-2021:0346MODERATE2020-04-02
RHSA-2021:0346 — Moderate
- Red HatRHSA-2021:0459MODERATE2020-04-02
RHSA-2021:0459 — Moderate
- Red HatRHSA-2021:0934MODERATE2020-04-02
RHSA-2021:0934 — Moderate
- UbuntuUSN-4372-1MEDIUM
QEMU vulnerabilities
- UbuntuUSN-7094-1MEDIUM
QEMU vulnerabilities
Data Freshness Timeline
(refreshed 5× in last 7d / 29× 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.
Showing the most recent 100 of 170 total refreshes for this CVE.
- 2026-10-05 17:39 UTCEPSS rescore
- 2026-10-03 14:22 UTCEPSS rescore
- 2026-10-02 16:22 UTCEPSS rescore
- 2026-09-30 15:14 UTCEG score recompute
- 2026-09-30 14:59 UTCEPSS rescore
- 2026-09-27 13:40 UTCEPSS rescore
- 2026-09-27 05:15 UTCOSV refresh
- 2026-09-26 15:54 UTCEPSS rescore
- 2026-09-26 00:20 UTCEPSS rescore
- 2026-09-24 14:00 UTCEPSS rescore
- 2026-09-24 14:00 UTCEPSS rescore
- 2026-09-22 14:43 UTCEPSS rescore
- 2026-09-21 20:28 UTCEPSS rescore
- 2026-09-20 20:11 UTCEPSS rescore
- 2026-09-18 19:23 UTCEPSS rescore
- 2026-09-17 19:22 UTCEPSS rescore
- 2026-09-17 19:22 UTCEPSS rescore
- 2026-09-16 14:04 UTCEPSS rescore
- 2026-09-15 03:06 UTCEPSS rescore
- 2026-09-15 03:06 UTCEPSS rescore
- 2026-09-13 16:42 UTCEPSS rescore
- 2026-09-12 14:56 UTCEPSS rescore
- 2026-09-11 14:48 UTCEPSS rescore
- 2026-09-11 09:32 UTCEPSS rescore
- 2026-09-10 09:29 UTCEPSS rescore
Show 75 moreShow fewer
- 2026-09-08 21:56 UTCEPSS rescore
- 2026-09-07 15:57 UTCEPSS rescore
- 2026-09-07 14:48 UTCOSV refresh
- 2026-09-06 13:44 UTCEPSS rescore
- 2026-09-05 15:24 UTCEPSS rescore
- 2026-09-04 13:57 UTCEPSS rescore
- 2026-09-04 05:03 UTCEPSS rescore
- 2026-09-02 14:08 UTCEPSS rescore
- 2026-09-01 03:32 UTCEPSS rescore
- 2026-08-30 19:14 UTCEPSS rescore
- 2026-08-30 01:18 UTCEPSS rescore
- 2026-08-27 14:21 UTCEPSS rescore
- 2026-08-26 14:42 UTCEPSS rescore
- 2026-08-25 13:45 UTCEPSS rescore
- 2026-08-21 23:45 UTCEPSS rescore
- 2026-08-20 23:45 UTCOSV refresh
- 2026-08-20 22:52 UTCEPSS rescore
- 2026-08-19 17:00 UTCEPSS rescore
- 2026-08-18 13:44 UTCEPSS rescore
- 2026-08-17 13:43 UTCEPSS rescore
- 2026-08-16 14:52 UTCEPSS rescore
- 2026-08-16 02:11 UTCEPSS rescore
- 2026-08-15 01:26 UTCEPSS rescore
- 2026-08-13 21:57 UTCEPSS rescore
- 2026-08-12 13:47 UTCEPSS rescore
- 2026-08-09 13:43 UTCEPSS rescore
- 2026-08-08 16:33 UTCEPSS rescore
- 2026-08-07 16:23 UTCEPSS rescore
- 2026-08-06 13:43 UTCEPSS rescore
- 2026-08-05 19:14 UTCEPSS rescore
- 2026-08-05 15:11 UTCOSV refresh
- 2026-08-04 15:06 UTCEPSS rescore
- 2026-08-04 10:34 UTCEPSS rescore
- 2026-08-03 10:32 UTCEPSS rescore
- 2026-08-02 02:23 UTCEPSS rescore
- 2026-08-01 04:12 UTCEPSS rescore
- 2026-07-30 16:25 UTCEPSS rescore
- 2026-07-30 01:27 UTCEPSS rescore
- 2026-07-28 15:32 UTCEPSS rescore
- 2026-07-27 14:06 UTCEPSS rescore
- 2026-07-26 14:51 UTCEPSS rescore
- 2026-07-25 14:15 UTCEPSS rescore
- 2026-07-25 14:14 UTCEPSS rescore
- 2026-07-24 14:14 UTCEPSS rescore
- 2026-07-23 14:15 UTCEPSS rescore
- 2026-07-23 14:15 UTCEPSS rescore
- 2026-07-23 01:50 UTCEG score recompute
- 2026-07-22 22:36 UTCEG score recompute▲ 1.00
- 2026-07-22 14:05 UTCEPSS rescore
- 2026-07-21 15:22 UTCEPSS rescore
- 2026-07-21 15:22 UTCEPSS rescore
- 2026-07-20 17:04 UTCEPSS rescore
- 2026-07-20 17:04 UTCEPSS rescore
- 2026-07-19 14:28 UTCEPSS rescore
- 2026-07-19 14:24 UTCOSV refresh
- 2026-07-19 02:26 UTCEPSS rescore
- 2026-07-19 02:26 UTCEPSS rescore
- 2026-07-18 10:02 UTCEPSS rescore
- 2026-07-16 16:59 UTCEPSS rescore
- 2026-07-15 16:55 UTCEPSS rescore
- 2026-07-15 01:57 UTCEPSS rescore
- 2026-07-13 22:27 UTCEPSS rescore
- 2026-07-13 22:27 UTCEPSS rescore
- 2026-07-13 06:10 UTCEPSS rescore
- 2026-07-13 06:10 UTCEPSS rescore
- 2026-07-12 05:44 UTCEPSS rescore
- 2026-07-11 08:25 UTCEPSS rescore
- 2026-07-11 08:25 UTCEPSS rescore
- 2026-07-09 19:07 UTCEPSS rescore
- 2026-07-08 15:12 UTCEPSS rescore
- 2026-07-07 13:43 UTCEPSS rescore
- 2026-07-07 13:43 UTCEPSS rescore
- 2026-07-06 16:25 UTCEPSS rescore
- 2026-07-06 16:25 UTCEPSS rescore
- 2026-07-06 02:21 UTCEPSS rescore
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownDebian:11:slirp4netns · Debian:11:libslirp
Same vendor
10 shownredhat:RHSA-2021:0346 · redhat:RHBA-2020:3172 · redhat:RHSA-2020:4079
Frequently asked(5)
What is CVE-2020-1983?
When was CVE-2020-1983 disclosed?
Is CVE-2020-1983 actively exploited?
What is the CVSS score of CVE-2020-1983?
How do I remediate CVE-2020-1983?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2020-1983
Is Your Infrastructure Affected by CVE-2020-1983?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.