CVE-2019-6778: Buffer Overflow

Published Jan 8, 2019
·
Updated

A heap buffer overflow issue was found in the SLiRP networking implementation of the QEMU emulator. It occurs in tcpemu() routine while emulating Identification protocol and copying message data to a socket buffer.

A user/process could use this flaw to crash the Qemu process on the host resulting in DoS or potentially execute arbitrary code with privileges of the QEMU process.

Upstream patch: --------------- -> https://lists.gnu.org/archive/html/qemu-devel/2019-01/msg03132.html

Reference: ---------- -> https://www.openwall.com/lists/oss-security/2019/01/24/5

Other sources

A heap buffer overflow issue was found in the SLiRP networking implementation of the QEMU emulator. It occurs in tcpemu() routine while emulating the Identification protocol and copying message data to a socket buffer. A user or process could use this flaw to crash the QEMU process on the host resulting in a DoS or potentially executing arbitrary code with privileges of the QEMU process.

In QEMU 3.0.0, tcpemu in slirp/tcpsubr.c has a heap-based buffer overflow.

Affected Software

15 affected componentsFixes available
redhat/qemu-kvm<2:0.12.1.2-2.506.el6_10.5
2:0.12.1.2-2.506.el6_10.5
redhat/qemu-kvm<10:1.5.3-160.el7_6.3
10:1.5.3-160.el7_6.3
redhat/qemu-kvm-rhev<10:2.12.0-33.el7
10:2.12.0-33.el7
redhat/qemu-kvm-rhev<10:2.12.0-18.el7_6.7
10:2.12.0-18.el7_6.7
Qemu Qemu=3.0.0
openSUSE Leap=15.0
openSUSE Leap=42.3
Fedoraproject Fedora=29
Fedoraproject Fedora=30
Canonical Ubuntu Linux=14.04
Canonical Ubuntu Linux=16.04
Canonical Ubuntu Linux=18.04
Canonical Ubuntu Linux=18.10
debian/qemu
1:5.2+dfsg-11+deb11u31:5.2+dfsg-11+deb11u51:7.2+dfsg-7+deb12u181:7.2+dfsg-7+deb12u151:10.0.7+ds-0+deb13u11:10.0.2+ds-2+deb13u11:10.2.1+ds-1
debian/slirp4netns
1.0.1-21.2.0-11.2.1-1.11.3.3-1

Event History

Jan 8, 2019
Data Sourced
via Red Hat·02:39 AM
DescriptionSeverityAffected Software
Jan 11, 2019
CVE Published
12:00 AM
Mar 17, 2019
CVE Published
via MITRE·06:00 PM
Data Sourced
via MITRE·06:00 PM
Description
Feb 23, 2026
Data Sourced
via Ubuntu·04:00 PM
RemedyDescriptionSeverityAffected Software
Data Sourced
via Debian·04:00 PM
DescriptionAffected Software
Data Sourced
via Launchpad·04:00 PM
Description

Parent advisories

This vulnerability appears in the following advisories.

Frequently Asked Questions

1

What is the severity of CVE-2019-6778?

CVE-2019-6778 has been rated as critical due to the potential for a heap buffer overflow leading to a crash of the QEMU process.

2

How do I fix CVE-2019-6778?

To mitigate CVE-2019-6778, upgrade QEMU to versions 2:0.12.1.2-2.506.el6_10.5 or higher for RHEL systems or the specific patched versions for Debian and Ubuntu as stated in the vulnerability advisory.

3

What systems are affected by CVE-2019-6778?

CVE-2019-6778 affects various versions of QEMU and QEMU KVM across multiple distributions including Red Hat, Debian, and Ubuntu.

4

What could happen if CVE-2019-6778 is exploited?

Exploitation of CVE-2019-6778 could allow an attacker to crash the QEMU process, leading to service disruption on the host.

5

Is there a workaround for CVE-2019-6778?

There is no official workaround for CVE-2019-6778; the only solution is to upgrade to a fixed version of QEMU.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203