Description
ncsi.c in libslirp through 4.3.1 has a buffer over-read because it tries to read a certain amount of header data even if that exceeds the total packet length.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libslirp | 4.4.0-1 | — |
| Debian 14 | qemu | 1:4.1-2 | — |
| Debian 13 | libslirp | 4.4.0-1 | — |
| Debian 13 | qemu | 1:4.1-2 | — |
| Debian 12 | libslirp | 4.4.0-1 | — |
| Debian 12 | qemu | 1:4.1-2 | — |
| Debian 10 | qemu | 1:3.1+dfsg-8+deb10u9 | DLA-3099-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | libslirp | 4.1.0-2ubuntu2.2 | USN-5009-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | SLOF | 20191022-3.git899d9883.module+el8.3.0+6423+e4cb6418 | RHSA-2021:1762 |
| RHEL 8 | hivex +6 | 1.3.18-20.module+el8.3.0+6423+e4cb6418 | RHSA-2021:1762 |
| RHEL 8 | libguestfs-winsupport | 8.2-1.module+el8.3.0+6423+e4cb6418 | RHSA-2021:1762 |
| RHEL 8 | libiscsi +2 | 1.18.0-8.module+el8.1.0+4066+0f1aadab | RHSA-2021:1762 |
| RHEL 8 | libnbd +5 | 1.2.2-1.module+el8.3.0+7353+9de0a3cc | RHSA-2021:1762 |
| RHEL 8 | libvirt +28 | 6.0.0-35.module+el8.4.0+10230+7a9b21e4 | RHSA-2021:1762 |
| RHEL 8 | libvirt-dbus | 1.3.0-2.module+el8.3.0+6423+e4cb6418 | RHSA-2021:1762 |
| RHEL 8 | nbdkit +13 | 1.16.2-4.module+el8.3.0+6922+fd575af8 | RHSA-2021:1762 |
| RHEL 8 | netcf +2 | 0.2.8-12.module+el8.1.0+4066+0f1aadab | RHSA-2021:1762 |
| RHEL 8 | perl-Sys-Virt +2 | 6.0.0-1.module+el8.3.0+6423+e4cb6418 | RHSA-2021:1762 |
| RHEL 8 | qemu-img +10 | 15:4.2.0-48.module+el8.4.0+10368+630e803b | RHSA-2021:1762 |
| RHEL 8 | seabios +2 | 1.13.0-2.module+el8.3.0+7353+9de0a3cc | RHSA-2021:1762 |
| RHEL 8 | sgabios +1 | 1:0.20170427git-3.module+el8.1.0+4066+0f1aadab | RHSA-2021:1762 |
| RHEL 8 | supermin +1 | 5.1.19-10.module+el8.3.0+6423+e4cb6418 | RHSA-2021:1762 |
| RHEL 8 | virt-dib +25 | 1:1.40.2-27.module+el8.4.0+9282+0bdec052 | RHSA-2021:1762 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | hivex +6 | 1.3.18-20.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1762 |
| AlmaLinux 8 | libguestfs-winsupport | 8.2-1.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1762 |
| AlmaLinux 8 | libiscsi +2 | 1.18.0-8.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1762 |
| AlmaLinux 8 | libnbd +5 | 1.2.2-1.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1762 |
| AlmaLinux 8 | libvirt-dbus | 1.3.0-2.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1762 |
| AlmaLinux 8 | nbdkit +13 | 1.16.2-4.module_el8.5.0+2608+72063365 | ALSA-2021:1762 |
| AlmaLinux 8 | netcf +2 | 0.2.8-12.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1762 |
| AlmaLinux 8 | ocaml-libguestfs +1 | 1:1.40.2-27.module_el8.4.0+2358+630e803b.alma | ALSA-2021:1762 |
| AlmaLinux 8 | perl-Sys-Virt +1 | 6.0.0-1.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1762 |
| AlmaLinux 8 | seabios +2 | 1.13.0-2.module_el8.5.0+2608+72063365 | ALSA-2021:1762 |
| AlmaLinux 8 | sgabios | 1:0.20170427git-3.module_el8.3.0+2048+e7a0a3ea | ALSA-2021:1762 |
| AlmaLinux 8 | sgabios-bin | 1:0.20170427git-3.module_el8.5.0+2608+72063365 | ALSA-2021:1762 |
| AlmaLinux 8 | supermin +1 | 5.1.19-10.module_el8.5.0+2608+72063365 | ALSA-2021:1762 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | hivex | 1.3.18-20.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
| Rocky Linux 8 | libguestfs | 1:1.40.2-27.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
| Rocky Linux 8 | libguestfs-winsupport | 8.2-1.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
| Rocky Linux 8 | libiscsi | 1.18.0-8.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
| Rocky Linux 8 | libnbd | 1.2.2-1.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
| Rocky Linux 8 | libvirt | 6.0.0-35.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
| Rocky Linux 8 | libvirt-dbus | 1.3.0-2.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
| Rocky Linux 8 | nbdkit | 1.16.2-4.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
| Rocky Linux 8 | netcf | 0.2.8-12.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
| Rocky Linux 8 | perl-Sys-Virt +1 | 6.0.0-1.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
| Rocky Linux 8 | qemu-kvm | 5:4.2.0-48.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
| Rocky Linux 8 | seabios | 1.13.0-2.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
| Rocky Linux 8 | sgabios | 1:0.20170427git-3.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
| Rocky Linux 8 | supermin | 5.1.19-10.module+el8.4.0+534+4680a14e | RLSA-2021:1762 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | qemu | 5.2.0-17.1 | SUSE-SU-2021:1942-1 |
| SLES 15 SP2 | qemu | 3.1.1.1-9.27.2 | SUSE-SU-2021:1918-1, SUSE-SU-2021:1893-1, SUSE-SU-2021:1243-1 |
| SLES 15 SP1 | qemu | 3.1.1.1-9.24.3 | SUSE-SU-2021:1918-1, SUSE-SU-2021:1245-1 |
| SLES 15 | qemu | 2.11.2-9.43.1 | SUSE-SU-2021:1895-1, SUSE-SU-2021:1244-1 |
| SLES 12 SP5 | qemu | 3.1.1.1-48.2 | SUSE-SU-2021:1837-1, SUSE-SU-2021:1242-1 |
Show 16 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP4 | qemu | 2.11.2-5.29.1 | SUSE-SU-2021:1947-1, SUSE-SU-2021:1241-1 |
| SLES for SAP 15 SP1 | qemu | 3.1.1.1-9.24.3 | SUSE-SU-2021:1918-1, SUSE-SU-2021:1245-1 |
| SLES for SAP 15 | qemu | 2.11.2-9.43.1 | SUSE-SU-2021:1895-1, SUSE-SU-2021:1244-1 |
| SLES for SAP 12 SP5 | qemu | 3.1.1.1-48.2 | SUSE-SU-2021:1837-1, SUSE-SU-2021:1242-1 |
| SLES for SAP 12 SP4 | qemu | 2.11.2-5.29.1 | SUSE-SU-2021:1947-1, SUSE-SU-2021:1241-1 |
| SLE Micro 5.1 | slirp4netns | 0.4.7-150100.3.18.1 | SUSE-SU-2023:0870-1 |
| SLE Micro 5.0 | qemu | 4.2.1-11.16.3 | SUSE-SU-2021:1893-1, SUSE-SU-2021:1243-1 |
| SLE HPC 15 SP1 | qemu | 3.1.1.1-9.24.3 | SUSE-SU-2021:1918-1, SUSE-SU-2021:1245-1 |
| SLE HPC 15 | qemu | 2.11.2-9.43.1 | SUSE-SU-2021:1895-1, SUSE-SU-2021:1244-1 |
| SUSE OpenStack Cloud Crowbar 9 | qemu | 2.11.2-5.29.1 | SUSE-SU-2021:1947-1, SUSE-SU-2021:1241-1 |
| SUSE OpenStack Cloud 9 | qemu | 2.11.2-5.29.1 | SUSE-SU-2021:1947-1, SUSE-SU-2021:1241-1 |
| SUSE Manager Server 4.0 | qemu | 3.1.1.1-9.24.3 | SUSE-SU-2021:1918-1, SUSE-SU-2021:1245-1 |
| SUSE Manager Retail Branch Server 4.0 | qemu | 3.1.1.1-9.24.3 | SUSE-SU-2021:1918-1, SUSE-SU-2021:1245-1 |
| SUSE Manager Proxy 4.0 | qemu | 3.1.1.1-9.24.3 | SUSE-SU-2021:1918-1, SUSE-SU-2021:1245-1 |
| SUSE Enterprise Storage 7 | slirp4netns | 0.4.7-150100.3.18.1 | SUSE-SU-2023:0870-1 |
| SUSE Enterprise Storage 6 | qemu | 3.1.1.1-9.24.3 | SUSE-SU-2021:1918-1, SUSE-SU-2021:1245-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | qemu | 6.1.0-32.1 | openSUSE-SU-2024:11287-1 |
| openSUSE Leap 15.3 | qemu | 5.2.0-17.1 | openSUSE-SU-2021:1942-1 |
| openSUSE Leap 15.2 | qemu +2 | 4.2.1-lp152.9.12.1 | openSUSE-SU-2021:1043-1, openSUSE-SU-2021:0600-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap Micro 5.3 | slirp4netns | 0.4.7-150100.3.18.1 | SUSE-SU-2023:0870-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | libslirp | 4.4.0-r0 | — |
| Alpine v3.23 | libslirp | 4.4.0-r0 | — |
| Alpine v3.22 | libslirp | 4.4.0-r0 | — |
| Alpine v3.21 | libslirp | 4.4.0-r0 | — |
| Alpine v3.20 | libslirp | 4.4.0-r0 | — |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | libslirp | 4.4.0-r0 | — |
| Alpine v3.18 | libslirp | 4.4.0-r0 | — |
| Alpine v3.17 | libslirp | 4.4.0-r0 | — |
| Alpine v3.16 | libslirp | 4.4.0-r0 | — |
| Alpine v3.15 | libslirp | 4.4.0-r0 | — |
| Alpine v3.14 | libslirp | 4.4.0-r0 | — |
| Alpine v3.13 | libslirp | 4.4.0-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | qemu +26 | 10:3.1.0-8.amzn2.0.8 | ALAS2-2021-1671 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | hivex +6 | 1.3.18-20.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 8 | libguestfs-winsupport | 8.2-1.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 8 | libiscsi +2 | 1.18.0-8.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 8 | libnbd +5 | 1.2.2-1.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 8 | libvirt +29 | 5.7.0-32.module+el8.5.0+20482+a450964e | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 8 | libvirt-dbus | 1.3.0-2.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 8 | nbdkit +13 | 1.16.2-4.0.1.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 8 | netcf +2 | 0.2.8-12.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 8 | perl-Sys-Virt | 4.5.0-5.module+el8.5.0+20482+a450964e | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 8 | qemu-img +10 | 15:4.2.0-48.module+el8.4.0+20158+f6690737 | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 8 | seabios +2 | 1.13.0-2.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 8 | sgabios +1 | 1:0.20170427git-3.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 8 | supermin +1 | 5.1.19-10.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 8 | virt-dib +25 | 1:1.40.2-27.0.1.module+el8.4.0+20093+03a97712 | ELSA-2022-9172, ELSA-2021-1762 |
| Oracle Linux 7 | qemu +12 | 15:4.2.1-4.el7 | ELSA-2021-9638, ELSA-2021-9034 |
Advisories 27
- ALSA-2021:1762 Moderate: virt:rhel and virt-devel:rhel security, bug fix, and enhancement update AlmaLinux Security Advisories · Nov 2, 2026
- WID-SEC-2022-1271 QEMU: Mehrere Schwachstellen ermöglichen Offenlegung von Informationen BSI CERT-Bund (WID) · Jun 29, 2026
- RHSA-2021:1762 Red Hat Security Advisory: virt:rhel and virt-devel:rhel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- USN-5009-1 libslirp vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-3099-1 qemu - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2021:1762 Moderate: virt:rhel and virt-devel:rhel security, bug fix, and enhancement update Rocky Linux Security Advisories · Feb 5, 2026
- SUSE-SU-2021:1837-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1243-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0600-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2023:0870-1 Security update for slirp4netns SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1893-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1245-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1947-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1241-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1043-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1895-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1242-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1918-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1244-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1942-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1942-1 Security update for qemu SUSE / openSUSE Security Updates · May 7, 2025
- openSUSE-SU-2024:11287-1 qemu-6.1.0-32.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- ELSA-2022-9172 Important: virt:kvm_utils security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Feb 25, 2022
- ELSA-2021-9638 Important: qemu security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jan 4, 2022
- ALAS2-2021-1671 Moderate: qemu security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jun 22, 2021
- ELSA-2021-1762 Moderate: virt:ol and virt-devel:rhel security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 25, 2021
- ELSA-2021-9034 Important: qemu security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Feb 8, 2021
References
- https://lists.freedesktop.org/archives/slirp/2020-November/000115.html
- [oss-security] 20201127 CVE-2020-29129 CVE-2020-29130 QEMU: slirp: out-of-bounds access while processing ARP/NCSI packets mailing-list
- FEDORA-2020-77f93f41be vendor-advisory
- FEDORA-2020-331e1318dd vendor-advisory
- [debian-lts-announce] 20220905 [SECURITY] [DLA 3099-1] qemu security update mailing-list