Vulnerabilities (CVE)

An issue was discovered in ide_dma_cb() in hw/ide/core.c in QEMU 2.4.0 through 4.2.0. The guest system can crash the QEMU process in the host system via a special SCSI_IOCTL_SEND_COMMAND. It hits an assertion that implies that the size of successful DMA transfers there must be a multiple of 512 (the size of a sector). NOTE: a member of the QEMU security team disputes the significance of this issue because a "privileged guest user has many ways to cause similar DoS effect, without triggering this ... An issue was discovered in ide_dma_cb() in hw/ide/core.c in QEMU 2.4.0 through 4.2.0. The guest system can crash the QEMU process in the host system via a special SCSI_IOCTL_SEND_COMMAND. It hits an assertion that implies that the size of successful DMA transfers there must be a multiple of 512 (the size of a sector). NOTE: a member of the QEMU security team disputes the significance of this issue because a "privileged guest user has many ways to cause similar DoS effect, without triggering this assert.

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libslirp 4.0.0, as used in QEMU 4.1.0, has a use-after-free in ip_reass in ip_input.c.

hw/display/bochs-display.c in QEMU 4.0.0 does not ensure a sufficient PCI config space allocation, leading to a buffer overflow involving the PCIe extended config space.

qemu-bridge-helper.c in QEMU 3.1 and 4.0.0 does not ensure that a network interface name (obtained from bridge.conf or a --br=bridge option) is limited to the IFNAMSIZ size, which can lead to an ACL bypass.

The QMP guest_exec command in QEMU 4.0.0 and earlier is prone to OS command injection, which allows the attacker to achieve code execution, denial of service, or information disclosure by sending a crafted QMP command to the listening server. Note: This has been disputed as a non-issue since QEMU's -qmp interface is meant to be used by trusted users. If one is able to access this interface via a tcp socket open to the internet, then it is an insecure configuration issue

The QMP migrate command in QEMU version 4.0.0 and earlier is vulnerable to OS command injection, which allows the remote attacker to achieve code execution, denial of service, or information disclosure by sending a crafted QMP command to the listening server. Note: This has been disputed as a non-issue since QEMU's -qmp interface is meant to be used by trusted users. If one is able to access this interface via a tcp socket open to the internet, then it is an insecure configuration issue

QEMU 3.0.0 has an Integer Overflow because the qga/commands*.c files do not check the length of the argument list or the number of environment variables. NOTE: This has been disputed as not exploitable

interface_release_resource in hw/display/qxl.c in QEMU 3.1.x through 4.0.0 has a NULL pointer dereference.

In QEMU 1:4.1-1, 1:2.1+dfsg-12+deb8u6, 1:2.8+dfsg-6+deb9u8, 1:3.1+dfsg-8~deb10u1, 1:3.1+dfsg-8+deb10u2, and 1:2.1+dfsg-12+deb8u12 (fixed), when executing script in lsi_execute_script(), the LSI scsi adapter emulator advances 's->dsp' index to read next opcode. This can lead to an infinite loop if the next opcode is empty. Move the existing loop exit after 10k iterations so that it covers no-op opcodes as well.

The ahci_commit_buf function in ide/ahci.c in QEMU allows attackers to cause a denial of service (NULL dereference) when the command header 'ad->cur_cmd' is null.

Quick Emulator (aka QEMU), when built with the Cirrus CLGD 54xx VGA Emulator support, allows local guest OS privileged users to cause a denial of service (out-of-bounds access and QEMU process crash) by leveraging incorrect region calculation when updating VGA display.

The load_multiboot function in hw/i386/multiboot.c in Quick Emulator (aka QEMU) allows local guest OS users to execute arbitrary code on the QEMU host via a mh_load_end_addr value greater than mh_bss_end_addr, which triggers an out-of-bounds read or write memory access.

The vga_draw_text function in Qemu allows local OS guest privileged users to cause a denial of service (out-of-bounds read and QEMU process crash) by leveraging improper memory address validation.

In QEMU 3.1.0, load_device_tree in device_tree.c calls the deprecated load_image function, which has a buffer overflow risk.

QEMU can have an infinite loop in hw/rdma/vmw/pvrdma_dev_ring.c because return values are not checked (and -1 is mishandled).

hw/rdma/vmw/pvrdma_main.c in QEMU does not implement a read operation (such as uar_read by analogy to uar_write), which allows attackers to cause a denial of service (NULL pointer dereference).

hw/rdma/vmw/pvrdma_cmd.c in QEMU allows create_cq and create_qp memory leaks because errors are mishandled.

hw/rdma/vmw/pvrdma_cmd.c in QEMU allows attackers to cause a denial of service (NULL pointer dereference or excessive memory allocation) in create_cq_ring or create_qp_rings.

hw/rdma/rdma_backend.c in QEMU allows guest OS users to trigger out-of-bounds access via a PvrdmaSqWqe ring element with a large num_sge value.

pvrdma_realize in hw/rdma/vmw/pvrdma_main.c in QEMU has a Memory leak after an initialisation error.

The Bluetooth subsystem in QEMU mishandles negative values for length variables, leading to memory corruption.

v9fs_wstat in hw/9pfs/9p.c in QEMU allows guest OS users to cause a denial of service (crash) because of a race condition during file renaming.

hw/9pfs/cofile.c and hw/9pfs/9p.c in QEMU can modify an fid path while it is being accessed by a second thread, leading to (for example) a use-after-free outcome.

The pnv_lpc_do_eccb function in hw/ppc/pnv_lpc.c in Qemu before 3.1 allows out-of-bounds write or read access to PowerNV memory.

In Qemu 3.0.0, lsi_do_msgin in hw/scsi/lsi53c895a.c allows out-of-bounds access by triggering an invalid msg_len value.

Qemu has integer overflows because IOReadHandler and its associated functions use a signed integer data type for a size value.

qemu_deliver_packet_iov in net/net.c in Qemu accepts packet sizes greater than INT_MAX, which allows attackers to cause a denial of service or possibly have unspecified other impact.

Qemu has a Buffer Overflow in pcnet_receive in hw/net/pcnet.c because an incorrect integer data type is used.

Qemu has a Buffer Overflow in rtl8139_do_receive in hw/net/rtl8139.c because an incorrect integer data type is used.

A flaw was found in qemu Media Transfer Protocol (MTP). The code opening files in usb_mtp_get_object and usb_mtp_get_partial_object and directories in usb_mtp_object_readdir doesn't consider that the underlying filesystem may have changed since the time lstat(2) was called in usb_mtp_object_alloc, a classical TOCTTOU problem. An attacker with write access to the host filesystem shared with a guest can use this property to navigate the host filesystem in the context of the QEMU process and read a ... A flaw was found in qemu Media Transfer Protocol (MTP). The code opening files in usb_mtp_get_object and usb_mtp_get_partial_object and directories in usb_mtp_object_readdir doesn't consider that the underlying filesystem may have changed since the time lstat(2) was called in usb_mtp_object_alloc, a classical TOCTTOU problem. An attacker with write access to the host filesystem shared with a guest can use this property to navigate the host filesystem in the context of the QEMU process and read any file the QEMU process has access to. Access to the filesystem may be local or via a network share protocol such as CIFS.

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A flaw was found in qemu Media Transfer Protocol (MTP) before version 3.1.0. A path traversal in the in usb_mtp_write_data function in hw/usb/dev-mtp.c due to an improper filename sanitization. When the guest device is mounted in read-write mode, this allows to read/write arbitrary files which may lead do DoS scenario OR possibly lead to code execution on the host.

An OOB heap buffer r/w access issue was found in the NVM Express Controller emulation in QEMU. It could occur in nvme_cmb_ops routines in nvme device. A guest user/process could use this flaw to crash the QEMU process resulting in DoS or potentially run arbitrary code with privileges of the QEMU process.

qemu-seccomp.c in QEMU might allow local OS guest users to cause a denial of service (guest crash) by leveraging mishandling of the seccomp policy for threads other than the main thread.

qmp_guest_file_read in qga/commands-posix.c and qga/commands-win32.c in qemu-ga (aka QEMU Guest Agent) in QEMU 2.12.50 has an integer overflow causing a g_malloc0() call to trigger a segmentation fault when trying to allocate a large memory chunk. The vulnerability can be exploited by sending a crafted QMP command (including guest-file-read with a large count value) to the agent via the listening socket.

m_cat in slirp/mbuf.c in Qemu has a heap-based buffer overflow via incoming fragmented datagrams.

Qemu emulator <= 3.0.0 built with the NE2000 NIC emulation support is vulnerable to an integer overflow, which could lead to buffer overflow issue. It could occur when receiving packets over the network. A user inside guest could use this flaw to crash the Qemu process resulting in DoS.

An assertion-failure flaw was found in Qemu before 2.10.1, in the Network Block Device (NBD) server's initial connection negotiation, where the I/O coroutine was undefined. This could crash the qemu-nbd server if a client sent unexpected data during connection negotiation. A remote user or process could use this flaw to crash the qemu-nbd server resulting in denial of service.

Quick Emulator (Qemu) built with the VirtFS, host directory sharing via Plan 9 File System (9pfs) support, is vulnerable to an improper access control issue. It could occur while accessing files on a shared host directory. A privileged user inside guest could use this flaw to access host file system beyond the shared folder and potentially escalating their privileges on a host.

An out-of-bounds memory access issue was found in Quick Emulator (QEMU) before 1.7.2 in the VNC display driver. This flaw could occur while refreshing the VNC display surface area in the 'vnc_refresh_server_surface'. A user inside a guest could use this flaw to crash the QEMU process.

A stack buffer overflow flaw was found in the Quick Emulator (QEMU) before 2.9 built with the Network Block Device (NBD) client support. The flaw could occur while processing server's response to a 'NBD_OPT_LIST' request. A malicious NBD server could use this issue to crash a remote NBD client resulting in DoS or potentially execute arbitrary code on client host with privileges of the QEMU process.