Qemu

A potential DoS flaw was found in the virtio-fs shared file system daemon (virtiofsd) implementation of the QEMU version >= v5.0. Virtio-fs is meant to share a host file system directory with a guest via virtio-fs device. If the guest opens the maximum number of file descriptors under the shared directory, a denial of service may occur. This flaw allows a guest user/process to cause this denial of service on the host.Show less

An integer overflow was found in QEMU 4.0.1 through 4.2.0 in the way it implemented ATI VGA emulation. This flaw occurs in the ati_2d_blt() routine in hw/display/ati-2d.c while handling MMIO write operations through the ati_mm_write() callback. A malicious guest could abuse this flaw to crash the QEMU process, resulting in a denial of service.Show less

QEMU 4.1.0 has a memory leak in zrle_compress_data in ui/vnc-enc-zrle.c during a VNC disconnect operation because libz is misused, resulting in a situation where memory allocated in deflateInit2 is not freed in deflateEnd.Show less

An out-of-bounds heap buffer access flaw was found in the way the iSCSI Block driver in QEMU versions 2.12.0 before 4.2.1 handled a response coming from an iSCSI server while checking the status of a Logical Address Block (LBA) in an iscsi_co_block_status() routine. A remote user could use this flaw to crash the QEMU process, resulting in a denial of service or potential execution of arbitrary code with privileges of the QEMU process on the host.Show less

The process_tx_desc function in hw/net/e1000.c in QEMU before 2.4.0.1 does not properly process transmit descriptor data when sending a network packet, which allows attackers to cause a denial of service (infinite loop and guest crash) via unspecified vectors.Show less

The ne2000_receive function in hw/net/ne2000.c in QEMU before 2.4.0.1 allows attackers to cause a denial of service (infinite loop and instance crash) or possibly execute arbitrary code via vectors related to receiving packets.Show less

tcp_emu in tcp_subr.c in libslirp 4.1.0, as used in QEMU 4.2.0, mismanages memory, as demonstrated by IRC DCC commands in EMU_IRC. This can cause a heap-based buffer overflow or other out-of-bounds access which can lead to a DoS or potential execute arbitrary code.Show less

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.Show less

A flaw was found in the way qemu v1.3.0 and later (virtio-rng) validates addresses when guest accesses the config space of a virtio device. If the virtio device has zero/small sized config space, such as virtio-rng, a privileged guest user could use this flaw to access the matching host's qemu address space and thus increase their privileges on the host.Show less

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.Show less

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 issueShow less