========================================================================== Ubuntu Security Notice USN-8412-2 June 16, 2026
qemu regression
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
Summary:
USN-8412-1 introduced a regression in QEMU
Software Description:
- qemu: Machine emulator and virtualizer
Details:
USN-8412-1 fixed vulnerabilities in QEMU. On both Ubuntu 18.04 LTS and
Ubuntu 20.04 LTS, the fix for CVE-2024-7409 was incomplete and resulted
in a regression that could cause qemu-nbd to crash when a client connected.
This update fixes the problem.
We apologize for the inconvenience.
Original advisory details:
Felipe Franciosi, Raphael Norwitz, and Peter Turschmid discovered that the
iSCSI block driver in QEMU incorrectly handled certain responses from an
iSCSI server. A remote attacker could possibly use this issue to cause QEMU
to crash, resulting in a denial of service, or possibly execute arbitrary
code. This issue only affected Ubuntu 14.04 LTS. (CVE-2020-1711)
It was discovered that the iSCSI block driver in QEMU incorrectly handled
certain memory operations, leading to a heap-based buffer over-read. An
attacker could possibly use this issue to expose sensitive information from
the host. This issue only affected Ubuntu 14.04 LTS. (CVE-2020-11947)
Ziming Zhang discovered that the SM501 display driver in QEMU contained an
integer overflow. A local attacker could possibly use this issue to cause
QEMU to crash, resulting in a denial of service. This issue only affected
Ubuntu 14.04 LTS. (CVE-2020-12829)
Gaoning Pan and Xingwei Li discovered that the USB xHCI controller
implementation in QEMU contained an infinite loop. An attacker inside the
guest could possibly use this issue to cause QEMU to hang, resulting in a
denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04
LTS, and Ubuntu 18.04 LTS. (CVE-2020-14394)
Lei Sun discovered that QEMU incorrectly handled certain MemoryRegionOps
objects, leading to a NULL pointer dereference. An attacker inside the
guest could possibly use this issue to cause QEMU to crash, resulting in a
denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu
16.04 LTS. (CVE-2020-15469)
Alexander Bulekov discovered that the e1000e network device implementation
in QEMU contained a use-after-free. An attacker inside the guest could
possibly use this issue to cause QEMU to crash, resulting in a denial of
service. This issue only affected Ubuntu 14.04 LTS. (CVE-2020-15859)
Ziming Zhang discovered that the XGMAC Ethernet controller in QEMU
contained a buffer overflow. An attacker inside the guest could possibly
use this issue to cause QEMU to crash, resulting in a denial of service, or
possibly execute arbitrary code. This issue only affected Ubuntu 14.04 LTS.
(CVE-2020-15863)
Alexander Bulekov discovered that the SDHCI device emulation in QEMU
contained a heap-based buffer overflow. An attacker inside the guest could
possibly use this issue to cause QEMU to crash, resulting in a denial of
service, or possibly execute arbitrary code. This issue only affected
Ubuntu 14.04 LTS. (CVE-2020-17380)
Sergej Schumilo, Cornelius Aschermann, and Simon Wörner discovered that the
USB xHCI controller implementation in QEMU did not check a return value,
leading to a use-after-free. An attacker inside the guest could possibly
use this issue to cause QEMU to crash, resulting in a denial of service.
This issue only affected Ubuntu 14.04 LTS. (CVE-2020-25084)
Gaoning Pan, Yongkang Jia, and Yi Ren discovered that the USB OHCI
controller implementation in QEMU contained a stack-based buffer over-read.
An attacker inside the guest could possibly use this issue to cause QEMU to
crash, resulting in a denial of service. This issue only affected Ubuntu
14.04 LTS. (CVE-2020-25624)
It was discovered that the USB OHCI controller implementation in QEMU
contained an infinite loop. An attacker inside the guest could possibly use
this issue to cause QEMU to consume resources, resulting in a denial of
service. This issue only affected Ubuntu 14.04 LTS. (CVE-2020-25625)
Cheolwoo Myung discovered that the USB EHCI emulation in QEMU did not
handle DMA memory map failures, leading to a reachable assertion. An
attacker inside the guest could possibly use this issue to cause QEMU to
crash, resulting in a denial of service. This issue only affected Ubuntu
14.04 LTS. (CVE-2020-25723)
Gaoning Pan discovered that the network device emulation in QEMU could be
made to trigger an assertion failure when processing packets that lacked a
valid layer 3 protocol. An attacker inside the guest could possibly use
this issue to cause QEMU to crash, resulting in a denial of service. This
issue only affected Ubuntu 14.04 LTS. (CVE-2020-27617)
Wenxiang Qian discovered that the ATAPI emulation in QEMU did not properly
validate a buffer index, leading to an out-of-bounds read. An attacker
inside the guest could possibly use this issue to expose sensitive
information or cause QEMU to crash, resulting in a denial of service. This
issue only affected Ubuntu 14.04 LTS. (CVE-2020-29443)
Cheolwoo Myung discovered that the ESP SCSI emulation in QEMU contained a
NULL pointer dereference. An attacker inside the guest could possibly use
this issue to cause QEMU to crash, resulting in a denial of service. This
issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2020-35504)
Cheolwoo Myung discovered that the am53c974 SCSI host bus adapter emulation
in QEMU contained a NULL pointer dereference. An attacker inside the guest
could possibly use this issue to cause QEMU to crash, resulting in a denial
of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS.
(CVE-2020-35505)
It was discovered that the SDHCI controller emulation in QEMU contained
out-of-bounds read and write issues. An attacker inside the guest could
possibly use this issue to cause QEMU to crash, resulting in a denial of
service, or possibly execute arbitrary code. This issue only affected
Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2021-3409)
It was discovered that several network device emulations in QEMU contained
an infinite loop when operating in loopback mode. An attacker inside the
guest could possibly use this issue to cause QEMU to crash, resulting in a
denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu
16.04 LTS. (CVE-2021-3416)
Alexander Bulekov discovered that the floppy disk emulation in QEMU
contained a heap-based buffer overflow. An attacker inside the guest could
possibly use this issue to expose sensitive information or cause QEMU to
crash, resulting in a denial of service. This issue only affected Ubuntu
14.04 LTS and Ubuntu 16.04 LTS. (CVE-2021-3507)
Remy Noel discovered that the USB redirector device emulation in QEMU
performed an unbounded stack allocation when combining USB packets. An
attacker inside the guest could possibly use this issue to cause QEMU to
crash, resulting in a denial of service. This issue only affected Ubuntu
14.04 LTS and Ubuntu 16.04 LTS. (CVE-2021-3527)
It was discovered that the QXL display device emulation in QEMU contained
an integer overflow, leading to a heap-based buffer overflow. An attacker
inside the guest could possibly use this issue to cause QEMU to crash,
resulting in a denial of service, or possibly execute arbitrary code. This
issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2021-4206)
It was discovered that the QXL display device emulation in QEMU performed a
double fetch of guest-controlled values, leading to a heap-based buffer
overflow. An attacker inside the guest could possibly use this issue to
cause QEMU to crash, resulting in a denial of service, or possibly execute
arbitrary code. This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04
LTS. (CVE-2021-4207)
It was discovered that the 9pfs server implementation in QEMU contained a
race condition, leading to a use-after-free. A malicious 9p client could
possibly use this issue to escalate privileges. This issue only affected
Ubuntu 14.04 LTS. (CVE-2021-20181)
Gaoning Pan discovered that the floppy disk emulation in QEMU contained a
NULL pointer dereference. An attacker inside the guest could possibly use
this issue to cause QEMU to crash, resulting in a denial of service. This
issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2021-20196)
Gaoning Pan discovered that the vmxnet3 network device emulation in QEMU
contained an integer overflow. An attacker inside the guest could possibly
use this issue to cause QEMU to crash, resulting in a denial of service.
This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS.
(CVE-2021-20203)
It was discovered that the ARM Generic Interrupt Controller emulation in
QEMU contained an out-of-bounds heap access. An attacker inside the guest
could possibly use this issue to cause QEMU to crash, resulting in a denial
of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS.
(CVE-2021-20221)
Alexander Bulekov, Cheolwoo Myung, Sergej Schumilo, Cornelius Aschermann,
and Simon Wörner discovered that the e1000 network device emulation in QEMU
contained an infinite loop. An attacker inside the guest could possibly use
this issue to cause QEMU to consume resources, resulting in a denial of
service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS.
(CVE-2021-20257)
It was discovered that the 9p passthrough file system implementation in
QEMU did not prevent opening special files on the host. A malicious guest
could possibly use this issue to escape the exported 9p tree. This issue
only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 18.04 LTS.
(CVE-2023-2861)
It was discovered that the virtio crypto device emulation in QEMU did not
properly validate certain buffer lengths, leading to a heap buffer
overflow. An attacker inside the guest could possibly use this issue to
cause QEMU to crash, resulting in a denial of service, or possibly execute
arbitrary code. This issue only affected Ubuntu 18.04 LTS. (CVE-2023-3180)
It was discovered that the built-in VNC server in QEMU contained a NULL
pointer dereference when cleaning up a connection that failed during the
handshake. A remote attacker could possibly use this issue to cause QEMU to
crash, resulting in a denial of service. This issue only affected Ubuntu
18.04 LTS. (CVE-2023-3354)
It was discovered that QEMU could incorrectly direct a guest I/O operation
to disk offset 0 instead of the intended offset. An attacker inside the
guest could possibly use this issue to read or overwrite sensitive data,
potentially gaining control of the host. This issue only affected Ubuntu
14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 18.04 LTS. (CVE-2023-5088)
It was discovered that several virtio device emulations in QEMU did not
properly guard against DMA reentrancy, leading to a double free. An
attacker inside the guest could possibly use this issue to cause QEMU to
crash, resulting in a denial of service, or possibly execute arbitrary
code. (CVE-2024-3446)
It was discovered that the SDHCI device emulation in QEMU contained a heap-
based buffer overflow. An attacker inside the guest could possibly use this
issue to cause QEMU to crash, resulting in a denial of service.
(CVE-2024-3447)
It was discovered that the QEMU disk image utility (qemu-img) did not
properly handle certain crafted image files. An attacker could possibly use
this issue to cause qemu-img to consume excessive resources or access an
unintended external file, resulting in a denial of service. This issue only
affected Ubuntu 20.04 LTS. (CVE-2024-4467)
Cyrille Chatras discovered that the LSI53C895A SCSI Host Bus Adapter
emulation in QEMU contained a use-after-free. An attacker inside the guest
could possibly use this issue to cause QEMU to crash, resulting in a denial
of service, or possibly execute arbitrary code. (CVE-2024-6519)
It was discovered that the NBD server in QEMU contained an improper
synchronization issue during socket closure. A remote attacker could
possibly use this issue to cause QEMU to crash, resulting in a denial of
service. (CVE-2024-7409)
It was discovered that the USB emulation in QEMU contained a reachable
assertion. An attacker inside the guest could possibly use this issue to
cause QEMU to crash, resulting in a denial of service. (CVE-2024-8354)
It was discovered that QEMU incorrectly handled resources during the VNC
WebSocket handshake, leading to a use-after-free. A remote attacker could
possibly use this issue to cause QEMU to crash, resulting in a denial of
service. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS.
(CVE-2025-11234)
It was discovered that QEMU could be made to read out of bounds when
reading VMDK images. An attacker could possibly use this issue to expose
sensitive information or cause QEMU to crash, resulting in a denial of
service. (CVE-2026-2243)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 20.04 LTS
qemu-block-extra 1:4.2-3ubuntu6.30+esm2
Available with Ubuntu Pro
qemu-utils 1:4.2-3ubuntu6.30+esm2
Available with Ubuntu Pro
Ubuntu 18.04 LTS
qemu-block-extra 1:2.11+dfsg-1ubuntu7.42+esm6
Available with Ubuntu Pro
qemu-utils 1:2.11+dfsg-1ubuntu7.42+esm6
Available with Ubuntu Pro
After a standard system update you need to restart all QEMU virtual
machines to make all the necessary changes.
References:
https://ubuntu.com/security/notices/USN-8412-2
https://ubuntu.com/security/notices/USN-8412-1
CVE-2024-7409
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