Description
An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw exists in the tftp_input() function and could occur while processing a udp packet that is smaller than the size of the 'tftp_t' structure. This issue may lead to out-of-bounds read access or indirect host memory disclosure to the guest. The highest threat from this vulnerability is to data confidentiality. This flaw affects libslirp versions prior to 4.6.0.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | QEMU | libslirp 4.6.0 | — |
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 | 4.6.1-1 | — |
| Debian 14 | qemu | 1:4.1-2 | — |
| Debian 13 | libslirp | 4.6.1-1 | — |
| Debian 13 | qemu | 1:4.1-2 | — |
| Debian 12 | libslirp | 4.6.1-1 | — |
| Debian 12 | qemu | 1:4.1-2 | — |
| Debian 10 | qemu | 1:3.1+dfsg-8+deb10u10 | DLA-3362-1 |
| Debian 9 | qemu | 1:2.8+dfsg-6+deb9u15 | DLA-2753-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | libslirp | 4.6.1-1 | — |
| Ubuntu 20.04 LTS | libslirp | 4.1.0-2ubuntu2.2 | USN-5009-1 |
| Ubuntu 20.04 LTS | qemu | 1:4.2-3ubuntu6.17 | USN-5010-1 |
| Ubuntu 18.04 LTS | qemu | 1:2.11+dfsg-1ubuntu7.37 | USN-5010-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | SLOF | 20191022-3.git899d9883.module+el8.3.0+6423+e4cb6418 | RHSA-2021:4191 |
| RHEL 8 | hivex +6 | 1.3.18-21.module+el8.5.0+10709+b3edb581 | RHSA-2021:4191 |
| RHEL 8 | libguestfs-winsupport | 8.2-1.module+el8.3.0+6423+e4cb6418 | RHSA-2021:4191 |
| RHEL 8 | libiscsi +2 | 1.18.0-8.module+el8.1.0+4066+0f1aadab | RHSA-2021:4191 |
| RHEL 8 | libnbd +5 | 1.2.2-1.module+el8.3.0+7353+9de0a3cc | RHSA-2021:4191 |
| RHEL 8 | libvirt +28 | 6.0.0-37.module+el8.5.0+12162+40884dd2 | RHSA-2021:4191 |
| RHEL 8 | libvirt-dbus | 1.3.0-2.module+el8.3.0+6423+e4cb6418 | RHSA-2021:4191 |
| RHEL 8 | nbdkit +13 | 1.16.2-4.module+el8.3.0+6922+fd575af8 | RHSA-2021:4191 |
| RHEL 8 | netcf +2 | 0.2.8-12.module+el8.1.0+4066+0f1aadab | RHSA-2021:4191 |
| RHEL 8 | perl-Sys-Virt +2 | 6.0.0-1.module+el8.3.0+6423+e4cb6418 | RHSA-2021:4191 |
| RHEL 8 | qemu-img +10 | 15:4.2.0-59.module+el8.5.0+12817+cb650d43 | RHSA-2021:4191 |
| RHEL 8 | seabios +2 | 1.13.0-2.module+el8.3.0+7353+9de0a3cc | RHSA-2021:4191 |
| RHEL 8 | sgabios +1 | 1:0.20170427git-3.module+el8.1.0+4066+0f1aadab | RHSA-2021:4191 |
| RHEL 8 | supermin +1 | 5.1.19-10.module+el8.3.0+6423+e4cb6418 | RHSA-2021:4191 |
| RHEL 8 | virt-dib +25 | 1:1.40.2-28.module+el8.5.0+10717+67be7ac4 | RHSA-2021:4191 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | hivex +4 | 1.3.18-21.module_el8.5.0+2608+72063365 | ALSA-2021:4191 |
| AlmaLinux 8 | libguestfs-winsupport | 8.2-1.module_el8.5.0+2608+72063365 | ALSA-2021:4191 |
| AlmaLinux 8 | libiscsi +2 | 1.18.0-8.module_el8.5.0+2608+72063365 | ALSA-2021:4191 |
| AlmaLinux 8 | libnbd +3 | 1.2.2-1.module_el8.5.0+2608+72063365 | ALSA-2021:4191 |
| AlmaLinux 8 | libvirt +28 | 6.0.0-37.module_el8.5.0+2608+72063365 | ALSA-2021:4191 |
| AlmaLinux 8 | libvirt-dbus | 1.3.0-2.module_el8.5.0+2608+72063365 | ALSA-2021:4191 |
| AlmaLinux 8 | nbdkit +13 | 1.16.2-4.module_el8.5.0+2608+72063365 | ALSA-2021:4191 |
| AlmaLinux 8 | netcf +2 | 0.2.8-12.module_el8.5.0+2608+72063365 | ALSA-2021:4191 |
| AlmaLinux 8 | perl-Sys-Virt +1 | 6.0.0-1.module_el8.5.0+2608+72063365 | ALSA-2021:4191 |
| AlmaLinux 8 | seabios +2 | 1.13.0-2.module_el8.5.0+2608+72063365 | ALSA-2021:4191 |
| AlmaLinux 8 | sgabios +1 | 1:0.20170427git-3.module_el8.5.0+2608+72063365 | ALSA-2021:4191 |
| AlmaLinux 8 | supermin +1 | 5.1.19-10.module_el8.5.0+2608+72063365 | ALSA-2021:4191 |
| AlmaLinux 8 | virt-dib +23 | 1:1.40.2-28.module_el8.5.0+2608+72063365.alma | ALSA-2021:4191 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | hivex | 1.3.18-21.module+el8.4.0+642+7e26f5e1 | RLSA-2021:4191 |
| Rocky Linux 8 | libguestfs | 1:1.40.2-28.module+el8.5.0+670+c4aa478c | RLSA-2021:4191 |
| Rocky Linux 8 | libguestfs-winsupport | 8.2-1.module+el8.4.0+534+4680a14e | RLSA-2021:4191 |
| Rocky Linux 8 | libiscsi | 1.18.0-8.module+el8.4.0+534+4680a14e | RLSA-2021:4191 |
| Rocky Linux 8 | libnbd | 1.2.2-1.module+el8.4.0+534+4680a14e | RLSA-2021:4191 |
| Rocky Linux 8 | libvirt | 6.0.0-37.module+el8.5.0+670+c4aa478c | RLSA-2021:4191 |
| Rocky Linux 8 | libvirt-dbus | 1.3.0-2.module+el8.4.0+534+4680a14e | RLSA-2021:4191 |
| Rocky Linux 8 | nbdkit | 1.16.2-4.module+el8.4.0+534+4680a14e | RLSA-2021:4191 |
| Rocky Linux 8 | netcf | 0.2.8-12.module+el8.4.0+534+4680a14e | RLSA-2021:4191 |
| Rocky Linux 8 | perl-Sys-Virt +1 | 6.0.0-1.module+el8.4.0+534+4680a14e | RLSA-2021:4191 |
| Rocky Linux 8 | qemu-kvm | 5:4.2.0-59.module+el8.5.0+670+c4aa478c | RLSA-2021:4191 |
| Rocky Linux 8 | seabios | 1.13.0-2.module+el8.4.0+534+4680a14e | RLSA-2021:4191 |
| Rocky Linux 8 | sgabios | 1:0.20170427git-3.module+el8.4.0+534+4680a14e | RLSA-2021:4191 |
| Rocky Linux 8 | supermin | 5.1.19-10.module+el8.4.0+534+4680a14e | RLSA-2021:4191 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP4 | libslirp | 4.3.1-150300.6.2 | SUSE-SU-2022:1730-1 |
| SLES 15 SP3 | libslirp | 4.3.1-150300.2.7.1 | SUSE-SU-2022:1730-1, SUSE-SU-2022:1465-1 |
| SLES 15 SP2 | qemu | 4.2.1-11.25.2 | SUSE-SU-2021:2474-1 |
| SLES 15 SP1 | qemu | 3.1.1.1-9.30.2 | SUSE-SU-2021:2591-1 |
| SLES 15 | qemu | 2.11.2-9.49.1 | SUSE-SU-2021:2461-1 |
Show 24 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | qemu | 3.1.1.1-54.1 | SUSE-SU-2021:2448-1 |
| SLES 12 SP5 | xen | 4.12.4_12-3.49.1 | SUSE-SU-2021:2924-1 |
| SLES 12 SP4 | qemu | 2.11.2-5.35.1 | SUSE-SU-2021:2546-1 |
| SLES 12 SP4 | xen | 4.11.4_20-2.60.1 | SUSE-SU-2021:2955-1 |
| SLES 12 SP3 | qemu | 2.9.1-6.53.1 | SUSE-SU-2021:2563-1 |
| SLES 12 SP3 | xen | 4.9.4_20-3.91.1 | SUSE-SU-2021:2957-1 |
| SLES 12 SP2 | qemu | 2.6.2-41.68.1 | SUSE-SU-2021:2428-1 |
| SLES 12 SP2 | xen | 4.7.6_16-43.79.5 | SUSE-SU-2021:3322-1 |
| SLES 11 SP4 | xen | 4.4.4_50-61.67.1 | SUSE-SU-2021:14848-1 |
| SLES for SAP 15 SP1 | qemu | 3.1.1.1-9.30.2 | SUSE-SU-2021:2591-1 |
| SLES for SAP 15 | qemu | 2.11.2-9.49.1 | SUSE-SU-2021:2461-1 |
| SLES for SAP 12 SP5 | qemu | 3.1.1.1-54.1 | SUSE-SU-2021:2448-1 |
| SLES for SAP 12 SP5 | xen | 4.12.4_12-3.49.1 | SUSE-SU-2021:2924-1 |
| SLES for SAP 12 SP4 | qemu | 2.11.2-5.35.1 | SUSE-SU-2021:2546-1 |
| SLES for SAP 12 SP4 | xen | 4.11.4_20-2.60.1 | SUSE-SU-2021:2955-1 |
| SLES for SAP 12 SP3 | qemu | 2.9.1-6.53.1 | SUSE-SU-2021:2563-1 |
| SLES for SAP 12 SP3 | xen | 4.9.4_20-3.91.1 | SUSE-SU-2021:2957-1 |
| SLE Micro 5.2 | libslirp | 4.3.1-150300.2.7.1 | SUSE-SU-2022:1730-1, SUSE-SU-2022:1465-1 |
| SLE Micro 5.1 | libslirp | 4.3.1-150300.2.7.1 | SUSE-SU-2022:1730-1, SUSE-SU-2022:1465-1 |
| SLE Micro 5.0 | qemu | 4.2.1-11.25.2 | SUSE-SU-2021:2474-1 |
| SLE HPC 15 SP1 | qemu | 3.1.1.1-9.30.2 | SUSE-SU-2021:2591-1 |
| SLE HPC 15 | qemu | 2.11.2-9.49.1 | SUSE-SU-2021:2461-1 |
| SUSE OpenStack Cloud Crowbar 9 | qemu | 2.11.2-5.35.1 | SUSE-SU-2021:2546-1 |
| SUSE OpenStack Cloud Crowbar 9 | xen | 4.11.4_20-2.60.1 | SUSE-SU-2021:2955-1 |
| SUSE OpenStack Cloud Crowbar 8 | qemu | 2.9.1-6.53.1 | SUSE-SU-2021:2563-1 |
| SUSE OpenStack Cloud Crowbar 8 | xen | 4.9.4_20-3.91.1 | SUSE-SU-2021:2957-1 |
| SUSE OpenStack Cloud 9 | qemu | 2.11.2-5.35.1 | SUSE-SU-2021:2546-1 |
| SUSE OpenStack Cloud 9 | xen | 4.11.4_20-2.60.1 | SUSE-SU-2021:2955-1 |
| SUSE OpenStack Cloud 8 | qemu | 2.9.1-6.53.1 | SUSE-SU-2021:2563-1 |
| SUSE OpenStack Cloud 8 | xen | 4.9.4_20-3.91.1 | SUSE-SU-2021:2957-1 |
| SUSE Manager Server 4.0 | qemu | 3.1.1.1-9.30.2 | SUSE-SU-2021:2591-1 |
| SUSE Manager Retail Branch Server 4.0 | qemu | 3.1.1.1-9.30.2 | SUSE-SU-2021:2591-1 |
| SUSE Manager Proxy 4.0 | qemu | 3.1.1.1-9.30.2 | SUSE-SU-2021:2591-1 |
| SUSE HPE Helion OpenStack 8 | qemu | 2.9.1-6.53.1 | SUSE-SU-2021:2563-1 |
| SUSE HPE Helion OpenStack 8 | xen | 4.9.4_20-3.91.1 | SUSE-SU-2021:2957-1 |
| SUSE Enterprise Storage 6 | qemu | 3.1.1.1-9.30.2 | SUSE-SU-2021:2591-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.4 | libslirp | 4.3.1-150300.2.7.1 | SUSE-SU-2022:1730-1, SUSE-SU-2022:1465-1 |
| openSUSE Leap 15.3 | libslirp | 4.3.1-150300.2.7.1 | SUSE-SU-2022:1730-1, SUSE-SU-2022:1465-1 |
| openSUSE Leap 15.3 | qemu | 3.1.1.1-9.30.2 | openSUSE-SU-2021:2591-1, openSUSE-SU-2021:2474-1 |
| openSUSE Leap 15.2 | qemu +2 | 4.2.1-lp152.9.20.1 | openSUSE-SU-2021:1202-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | libslirp | 4.6.0-r0 | — |
| Alpine v3.23 | libslirp | 4.6.0-r0 | — |
| Alpine v3.22 | libslirp | 4.6.0-r0 | — |
| Alpine v3.21 | libslirp | 4.6.0-r0 | — |
| Alpine v3.20 | libslirp | 4.6.0-r0 | — |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | libslirp | 4.6.0-r0 | — |
| Alpine v3.18 | libslirp | 4.6.0-r0 | — |
| Alpine v3.17 | libslirp | 4.6.0-r0 | — |
| Alpine v3.16 | libslirp | 4.6.0-r0 | — |
| Alpine v3.15 | libslirp | 4.6.0-r0 | — |
| Alpine v3.14 | libslirp | 4.6.0-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | qemu +26 | 10:3.1.0-8.amzn2.0.12 | ALAS2-2023-2169 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | hivex +6 | 1.3.18-21.module+el8.5.0+20365+3abb8f5b | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 8 | libguestfs-winsupport | 8.2-1.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 8 | libiscsi +2 | 1.18.0-8.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 8 | libnbd +5 | 1.2.2-1.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 8 | libvirt +29 | 5.7.0-32.module+el8.5.0+20482+a450964e | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 8 | libvirt-dbus | 1.3.0-2.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 8 | nbdkit +13 | 1.16.2-4.0.1.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 8 | netcf +2 | 0.2.8-12.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 8 | perl-Sys-Virt | 4.5.0-5.module+el8.5.0+20482+a450964e | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 8 | qemu-img +10 | 15:4.2.0-59.module+el8.5.0+20410+46b2d321 | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 8 | seabios +2 | 1.13.0-2.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 8 | sgabios +1 | 1:0.20170427git-3.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 8 | supermin +1 | 5.1.19-10.module+el8.3.0+7860+a7792d29 | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 8 | virt-dib +25 | 1:1.40.2-28.0.1.module+el8.5.0+20363+3abb8f5b | ELSA-2022-9172, ELSA-2021-4191 |
| Oracle Linux 7 | qemu +11 | 15:4.2.1-13.el7 | ELSA-2021-9638 |
Advisories 30
- ALSA-2021:4191 Moderate: virt:rhel and virt-devel:rhel security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- WID-SEC-2022-1219 QEMU: Mehrere Schwachstellen ermöglichen Offenlegung von Informationen BSI CERT-Bund (WID) · Jul 8, 2026
- RHSA-2021:4191 Red Hat Security Advisory: virt:rhel and virt-devel:rhel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- WID-SEC-2026-0778 Dell Secure Connect Gateway Policy Manager: Mehrere Schwachstellen BSI CERT-Bund (WID) · May 11, 2026
- USN-5009-1 libslirp vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- USN-5010-1 qemu vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-3362-1 qemu - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2753-1 qemu - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2021:4191 Moderate: virt:rhel and virt-devel:rhel security, bug fix, and enhancement update Rocky Linux Security Advisories · Feb 5, 2026
- SUSE-SU-2021:2955-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2924-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:2591-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2474-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:2474-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:3322-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2546-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2563-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2591-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2461-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1202-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:1730-1 Security update for libslirp SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2428-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2448-1 Security update for qemu SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2957-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2022:1465-1 Security update for libslirp SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:14848-1 Security update for xen SUSE / openSUSE Security Updates · May 2, 2025
- ALAS2-2023-2169 Low: qemu security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jul 25, 2023
- 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
- ELSA-2021-4191 Moderate: virt:ol and virt-devel:ol security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 16, 2021
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1970489
- FEDORA-2021-71de23bedd vendor-advisory
- FEDORA-2021-7cd749f133 vendor-advisory
- GLSA-202107-44 vendor-advisory
- https://security.netapp.com/advisory/ntap-20210805-0004/
- [debian-lts-announce] 20210902 [SECURITY] [DLA 2753-1] qemu security update mailing-list
- [debian-lts-announce] 20230314 [SECURITY] [DLA 3362-1] qemu security update mailing-list