Qemu-kvm: 'qemu-img info' leads to host file read/write
A flaw was found in the QEMU disk image utility (qemu-img) 'info' command. A specially crafted image file containing a `json:{}` value describing block devices in QMP could cause the qemu-img process on the host to consume large amounts of memory or CPU time, leading to denial of service or read/write to an existing external file.
USN-6567-1 fixed vulnerabilities QEMU. The fix for CVE-2023-2861 was too
restrictive and introduced a behaviour change leading to a regression in
certain environments. This update fixes the problem.
Original advisory details:
Gaoning Pan and Xingwei Li discovered that QEMU incorrectly handled the
USB xHCI controller device. A privileged guest attacker could possibly use
this issue to cause QEMU to crash, leading to a denial of service. This
issue only affected Ubuntu 20.04 LTS and Ubuntu 22.04 LTS. (CVE-2020-14394)
It was discovered that QEMU incorrectly handled the TCG Accelerator. A
local attacker could use this issue to cause QEM
Qemu: virtio: dma reentrancy issue leads to double free vulnerability
A double free vulnerability was found in QEMU virtio devices (virtio-gpu, virtio-serial-bus, virtio-crypto), where the mem_reentrancy_guard flag insufficiently protects against DMA reentrancy issues. This issue could allow a malicious privileged guest user to crash the QEMU process on the host, resulting in a denial of service or allow arbitrary code execution within the context of the QEMU process on the host.
QEMU before 8.2.0 has an integer underflow, and resultant buffer overflow, via a TI command when an expected non-DMA transfer length is less than the length of the available FIFO data. This occurs in esp_do_nodma in hw/scsi/esp.c because of an underflow of async_len.
Qemu: vnc: null pointer dereference in qemu_clipboard_request()
A flaw was found in the QEMU built-in VNC server while processing ClientCutText messages. The qemu_clipboard_request() function can be reached before vnc_server_cut_text_caps() was called and had the chance to initialize the clipboard peer, leading to a NULL pointer dereference. This could allow a malicious authenticated VNC client to crash QEMU and trigger a denial of service.
Qemu: virtio-net: stack buffer overflow in virtio_net_flush_tx()
A stack based buffer overflow was found in the virtio-net device of QEMU. This issue occurs when flushing TX in the virtio_net_flush_tx function if guest features VIRTIO_NET_F_HASH_REPORT, VIRTIO_F_VERSION_1 and VIRTIO_NET_F_MRG_RXBUF are enabled. This could allow a malicious user to overwrite local variables allocated on the stack. Specifically, the `out_sg` variable could be used to read a part of process memory and send it to the wire, causing an information leak.
Qemu: 9pfs: improper access control on special files
A flaw was found in the 9p passthrough filesystem (9pfs) implementation in QEMU. The 9pfs server did not prohibit opening special files on the host side, potentially allowing a malicious client to escape from the exported 9p tree by creating and opening a device file in the shared folder.
Qemu: improper ide controller reset can lead to mbr overwrite
A bug in QEMU could cause a guest I/O operation otherwise addressed to an arbitrary disk offset to be targeted to offset 0 instead (potentially overwriting the VM's boot code). This could be used, for example, by L2 guests with a virtual disk (vdiskL2) stored on a virtual disk of an L1 (vdiskL1) hypervisor to read and/or write data to LBA 0 of vdiskL1, potentially gaining control of L1 at its next reboot.
Qemu: vnc: infinite loop in inflate_buffer() leads to denial of service
A flaw was found in the QEMU built-in VNC server while processing ClientCutText messages. A wrong exit condition may lead to an infinite loop when inflating an attacker controlled zlib buffer in the `inflate_buffer` function. This could allow a remote authenticated client who is able to send a clipboard to the VNC server to trigger a denial of service.
Triggerable assertion due to race condition in hot-unplug
A flaw was found in QEMU. The async nature of hot-unplug enables a race scenario where the net device backend is cleared before the virtio-net pci frontend has been unplugged. A malicious guest could use this time window to trigger an assertion and cause a denial of service.
Heap buffer overflow in virtio_crypto_sym_op_helper()
A flaw was found in the QEMU virtual crypto device while handling data encryption/decryption requests in virtio_crypto_handle_sym_req. There is no check for the value of `src_len` and `dst_len` in virtio_crypto_sym_op_helper, potentially leading to a heap buffer overflow when the two values differ.
Qemu: 9pfs: suid/sgid bits not dropped on file write
A flaw was found in the 9p passthrough filesystem (9pfs) implementation in QEMU. When a local user in the guest writes an executable file with SUID or SGID, none of these privileged bits are correctly dropped. As a result, in rare circumstances, this flaw could be used by malicious users in the guest to elevate their privileges within the guest and help a host local user to elevate privileges on the host.
Qemu: e1000e: heap use-after-free in e1000e_write_packet_to_guest()
A DMA reentrancy issue leading to a use-after-free error was found in the e1000e NIC emulation code in QEMU. This issue could allow a privileged guest user to crash the QEMU process on the host, resulting in a denial of service.
Improper i/o watch removal in tls handshake can lead to remote unauthenticated denial of service
A flaw was found in the QEMU built-in VNC server. When a client connects to the VNC server, QEMU checks whether the current number of connections crosses a certain threshold and if so, cleans up the previous connection. If the previous connection happens to be in the handshake phase and fails, QEMU cleans up the connection again, resulting in a NULL pointer dereference issue. This could allow a remote unauthenticated client to cause a denial of service.
Qemu: pvrdma: out-of-bounds read in pvrdma_ring_next_elem_read()
A flaw was found in the QEMU implementation of VMWare's paravirtual RDMA device. This flaw allows a crafted guest driver to allocate and initialize a huge number of page tables to be used as a ring of descriptors for CQ and async events, potentially leading to an out-of-bounds read and crash of QEMU.
Qemu: lsi53c895a: dma reentrancy issue leads to stack overflow
A vulnerability in the lsi53c895a device affects the latest version of qemu. A DMA-MMIO reentrancy problem may lead to memory corruption bugs like stack overflow or use-after-free.
An out-of-bounds read flaw was found in the QXL display device emulation in QEMU. The qxl_phys2virt() function does not check the size of the structure pointed to by the guest physical address, potentially reading past the end of the bar space into adjacent pages. A malicious guest user could use this flaw to crash the QEMU process on the host causing a denial of service condition.
Высокий · CVSS 8.6EPSS 0,91%Нет опубликованного исправления
CVE-2022-3872
An off-by-one read/write issue was found in the SDHCI device of QEMU. It occurs when reading/writing the Buffer Data Port Register in sdhci_read_dataport and sdhci_write_dataport, respectively, if data_count == block_size. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition.
An integer underflow issue was found in the QEMU VNC server while processing ClientCutText messages in the extended format. A malicious client could use this flaw to make QEMU unresponsive by sending a specially crafted payload message, resulting in a denial of service.
A flaw was found in the QEMU virtio-fs shared file system daemon (virtiofsd) implementation. This flaw is strictly related to CVE-2018-13405. A local guest user can create files in the directories shared by virtio-fs with unintended group ownership in a scenario where a directory is SGID to a certain group and is writable by a user who is not a member of the group. This could allow a malicious unprivileged user inside the guest to gain access to resources accessible to the root group, potentially escalating their privileges within the guest. A malicious local user in the host might also leverage this unexpected executable file created by the