CVE-2020-10756

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.

Published: 2020-07-09 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-10756 is rated Moderate Risk (40.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.51%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-10756

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.51% +0.48%
2 2025-11-21 0.07% 0.03% -0.04%
3 2025-11-18 0.07%

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-10756

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
2.0 4.0 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
3.9 2.9 [email protected]

Weakness enumeration for CVE-2020-10756

OS Trackers for CVE-2020-10756

vendor priority summary link
alpine medium CVE-2020-10756: 1 source package rows (libslirp); 9 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 2. https://security.alpinelinux.org/vuln/CVE-2020-10756
debian not yet assigned CVE-2020-10756 not yet assigned priority: Debian including 3 source packages (libslirp, qemu, slirp4netns), 15 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 15. https://security-tracker.debian.org/tracker/CVE-2020-10756
redhat medium https://access.redhat.com/security/cve/CVE-2020-10756
suse medium https://www.suse.com/security/cve/CVE-2020-10756/
ubuntu medium CVE-2020-10756 medium priority: Ubuntu including 4 source packages (libslirp, qemu, qemu-kvm, slirp4netns), 68 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 36, DNE 23, needs-triage 3, released 3, ignored 2, needed 1. https://ubuntu.com/security/CVE-2020-10756

Affected software / configurations for CVE-2020-10756

Vendor Product Version Raw CPE
libslirp_project libslirp < 4.3.1 cpe:2.3:a:libslirp_project:libslirp:*:*:*:*:*:*:*:*
redhat openstack 13 cpe:2.3:a:redhat:openstack:13:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:advanced_virtualization:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 20.04 cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
opensuse leap 15.0 cpe:2.3:o:opensuse:leap:15.0:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*

References for CVE-2020-10756

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00035.html Mailing List Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00040.html Mailing List Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1835986 Issue Tracking Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00020.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JYTZ32P67PZER6P7TW6FQK3SZRKQLVEI/
https://security.netapp.com/advisory/ntap-20201001-0001/ Third Party Advisory
https://usn.ubuntu.com/4437-1/ Third Party Advisory
https://usn.ubuntu.com/4467-1/ Third Party Advisory
https://www.debian.org/security/2020/dsa-4728 Mailing List Third Party Advisory
https://www.zerodayinitiative.com/advisories/ZDI-20-1005/ Third Party Advisory VDB Entry
cvelogic Threat Intelligence