Skip to content
Fencer Vulns
medium 6.5

CVE-2020-10756 json

An out-of-bounds read vulnerability was found in the SLiRP networking implementation of the QEMU emulator.

published 2020-07-09 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-3173

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits
0
none known

Summary

An out-of-bounds read vulnerability was found in the SLiRP networking implementation of the QEMU emulator. This flaw occurs in the icmp6_send_echoreply() routine while replying to an ICMP echo request, also known as ping. This flaw allows a malicious guest to leak the contents of the host memory, resulting in possible information disclosure. This flaw affects versions of libslirp before 4.3.1.

Patch / fix

  • libslirp_project libslirp 4.3.1
  • qemu Debian 14, Debian 13, Debian 12 1:4.1-2
  • libslirp Debian 14, Debian 13, Debian 12 4.3.1-1
  • slirp4netns Debian 14, Debian 13, Debian 12 1.0.1-1

debian advisories DEBIAN-CVE-2020-10756

  • qemu Ubuntu 18.04 LTS 1:2.11+dfsg-1ubuntu7.31
  • libslirp Ubuntu 20.04 LTS 4.1.0-2ubuntu2.1

ubuntu advisories UBUNTU-CVE-2020-10756

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • crit RHEL 8 3.14-2.module+el8.3.0+8221+97165c3f
  • criu RHEL 8 3.14-2.module+el8.3.0+8221+97165c3f
  • crun RHEL 8 0.14.1-2.module+el8.3.0+8221+97165c3f
  • runc RHEL 8 1.0.0-68.rc92.module+el8.3.0+8221+97165c3f
  • udica RHEL 8 0.2.2-1.module+el8.3.0+8221+97165c3f
  • conmon RHEL 8 2:2.0.20-2.module+el8.3.0+8221+97165c3f
  • podman RHEL 8 2.0.5-5.module+el8.3.0+8221+97165c3f
  • skopeo RHEL 8 1:1.1.1-3.module+el8.3.0+8221+97165c3f

red hat advisories RHSA-2020:4694RHSA-2020:4059RHSA-2020:3586

  • qemu SLES for SAP 12 SP4, SLES 12 SP4-LTSS, OpenStack Cloud Crowbar 9 +1 more 2.11.2-5.32.1
  • qemu SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLES 15 SP1-BCL +7 more 3.1.1.1-9.27.2
  • qemu SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 2.11.2-9.46.1
  • qemu SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +3 more 2.9.1-6.50.1
  • qemu SLE Module for Server Applications 15 SP2, SLE Module for Basesystem 15 SP2, SLE Micro 5.0 4.2.1-11.19.2
  • qemu SLES for SAP 12 SP5, SLES 12 SP5 3.1.1.1-51.1
  • qemu SLES 12 SP2-BCL 2.6.2-41.65.1
  • slirp4netns SLE Module for Containers 15 SP2, SLE Module for Containers 15 SP1 0.4.7-3.12.1

suse advisories SUSE-SU-2021:1947-1SUSE-SU-2021:1918-1SUSE-SU-2021:1895-1SUSE-SU-2021:1894-1SUSE-SU-2021:1893-1SUSE-SU-2021:1837-1

  • libslirp openSUSE Tumbleweed 4.6.1+7-1.2
  • qemu openSUSE Leap 15.2 4.2.1-lp152.9.16.2
  • qemu-testsuite openSUSE Leap 15.2 4.2.1-lp152.9.16.7
  • qemu-linux-user openSUSE Leap 15.2 4.2.1-lp152.9.16.1
  • slirp4netns openSUSE Leap 15.2 0.4.7-lp152.2.3.1
  • slirp4netns openSUSE Leap 15.1 0.4.7-lp151.2.12.1

opensuse advisories openSUSE-SU-2024:10991-1openSUSE-SU-2021:1043-1openSUSE-SU-2020:0994-1openSUSE-SU-2020:0987-1

  • hivex AlmaLinux 8 1.3.18-20.module_el8.3.0+2048+e7a0a3ea
  • netcf AlmaLinux 8 0.2.8-12.module_el8.5.0+2608+72063365
  • netcf AlmaLinux 8 0.2.8-12.module_el8.6.0+2880+7d9e3703
  • netcf AlmaLinux 8 0.2.8-12.module_el8.3.0+2048+e7a0a3ea
  • libnbd AlmaLinux 8 1.2.2-1.module_el8.5.0+2608+72063365
  • libnbd AlmaLinux 8 1.2.2-1.module_el8.3.0+2048+e7a0a3ea
  • nbdkit AlmaLinux 8 1.16.2-4.module_el8.5.0+2608+72063365
  • nbdfuse AlmaLinux 8 1.2.2-1.module_el8.3.0+2048+e7a0a3ea

almalinux advisories ALSA-2021:1064ALSA-2020:4694ALSA-2020:4059

  • toolbox Rocky Linux 8 0.0.8-1.module+el8.4.0+556+40122d08
  • libslirp Rocky Linux 8 4.3.1-1.module+el8.7.0+1076+9b1c11c1
  • libslirp Rocky Linux 8 4.3.1-1.module+el8.4.0+556+40122d08
  • libslirp Rocky Linux 8 4.3.1-1.module+el8.5.0+709+440d5e7e
  • libslirp Rocky Linux 8 4.3.1-1.module+el8.6.0+783+10209741
  • python-podman-api Rocky Linux 8 1.2.0-0.2.gitd0a45fe.module+el8.5.0+770+e2f49861
  • python-podman-api Rocky Linux 8 1.2.0-0.2.gitd0a45fe.module+el8.4.0+559+c02fa3b2
  • python-podman-api Rocky Linux 8 1.2.0-0.2.gitd0a45fe.module+el8.5.0+708+6758137d

rocky linux advisories RLSA-2020:4694RLSA-2020:4059

  • libslirp Alpine 3.24, Alpine 3.23, Alpine 3.22 +9 more 4.3.1-r0

alpine advisories ALPINE-CVE-2020-10756

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-10756 updated cvss 6.5

QEMU: slirp: networking out-of-bounds read information disclosure vulnerability

  • Red Hat Enterprise Linux 5 kvm
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 qemu-img-ma, qemu-kvm-ma, slirp4netns, qemu-kvm-rhev, qemu-kvm-tools-ma, qemu-kvm-common-ma
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 8 slirp4netns
    affected: no fix available, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 Advanced Virtualization qemu-img, qemu-kvm, qemu-kiwi, qemu-kvm-core, qemu-kvm-tests, qemu-kvm-common, +9 more
    affected: no fix available
  • Red Hat OpenShift Container Platform 4 slirp4netns
    affected: no fix available “Fix deferred”
  • Red Hat OpenStack Platform 10 (Newton) qemu-img-rhev, qemu-kvm-rhev, qemu-kvm-tools-rhev, qemu-kvm-common-rhev Red Hat OpenStack Platform 13 (Queens) qemu-img-rhev, qemu-kvm-rhev, qemu-kvm-tools-rhev, qemu-kvm-common-rhev
    affected: no fix planned “Will not fix”
  • Red Hat Advanced Virtualization CodeReady Builder for RHEL 8.2.1 libnbd 1.2.2-1.module+el8.2.0+5644+32ac38d4, netcf 0.2.8-12.module+el8.2.0+4793+b09dd2fb, hivex 1.3.18-20.module+el8.2.0+5588+63a201c3, nbdfuse 1.2.2-1.module+el8.2.0+5644+32ac38d4, seabios 1.13.0-2.module+el8.2.1+7284+aa32a2c4, libiscsi 1.18.0-8.module+el8.2.0+4793+b09dd2fb, +45 more Red Hat Advanced Virtualization for RHEL 8.2.1 libnbd 1.2.2-1.module+el8.2.0+5644+32ac38d4, netcf 0.2.8-12.module+el8.2.0+4793+b09dd2fb, hivex 1.3.18-20.module+el8.2.0+5588+63a201c3, nbdfuse 1.2.2-1.module+el8.2.0+5644+32ac38d4, nbdkit 1.16.2-4.module+el8.2.1+6710+effcb1df, seabios 1.13.0-2.module+el8.2.1+7284+aa32a2c4, +96 more
    fixed: vendor fix RHSA-2020:3586
  • Red Hat CodeReady Linux Builder (v. 8) hivex 1.3.15-7.module+el8.1.0+4066+0f1aadab, netcf 0.2.8-12.module+el8.1.0+4066+0f1aadab, libvirt 4.5.0-42.module+el8.2.0+6024+15a2423f, seabios 1.11.1-4.module+el8.1.0+4066+0f1aadab, libiscsi 1.18.0-8.module+el8.1.0+4066+0f1aadab, netcf-libs 0.2.8-12.module+el8.1.0+4066+0f1aadab, +34 more Red Hat Enterprise Linux AppStream (v. 8) crit 3.14-2.module+el8.3.0+8221+97165c3f, criu 3.14-2.module+el8.3.0+8221+97165c3f, crun 0.14.1-2.module+el8.3.0+8221+97165c3f, udica 0.2.2-1.module+el8.3.0+8221+97165c3f, hivex 1.3.15-7.module+el8.1.0+4066+0f1aadab, nbdkit 1.4.2-5.module+el8.1.0+4066+0f1aadab, +106 more
    fixed: vendor fix RHSA-2020:4059
show 1 more
  • Red Hat Enterprise Linux 6 qemu-img, qemu-kvm, qemu-kvm-tools, qemu-guest-agent, qemu-guest-agent-win32 Red Hat Enterprise Linux 7 qemu-img, qemu-kvm, libcacard, qemu-kvm-tools, libcacard-tools, qemu-kvm-common, +1 more Red Hat Enterprise Linux 9 qemu-img, qemu-kvm, qemu-kvm-core, qemu-kvm-tools, qemu-pr-helper, qemu-kvm-common, +16 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
NVD 2.0 2.1 AV:L/AC:L/Au:N/C:P/I:N/A:N

Affected products

  • n/a Slirp

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.