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

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.

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.

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.

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

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.

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 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.

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 rtl8139_do_receive in hw/net/rtl8139.c because an incorrect integer data type is used.

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.

Stack-based buffer overflow in the vrend_decode_set_framebuffer_state function in vrend_decode.c in virglrenderer before 926b9b3460a48f6454d8bbe9e44313d86a65447f, as used in Quick Emulator (QEMU), allows a local guest users to cause a denial of service (application crash) via the "nr_cbufs" argument.