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 guest to escalate their privileges on the host system.
A use-after-free vulnerability was found in the LSI53C895A SCSI Host Bus Adapter emulation of QEMU. The flaw occurs while processing repeated messages to cancel the current SCSI request via the lsi_do_msgout function. This flaw allows a malicious privileged user within the guest to crash the QEMU process on the host, resulting in a denial of service.
A DMA reentrancy issue was found in the NVM Express Controller (NVME) emulation in QEMU. This CVE is similar to CVE-2021-3750 and, just like it, when the reentrancy write triggers the reset function nvme_ctrl_reset(), data structs will be freed leading to a use-after-free issue. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition or, potentially, executing arbitrary code within the context of the QEMU process on the host.
A stack overflow vulnerability was found in the Intel HD Audio device (intel-hda) of QEMU. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition. The highest threat from this vulnerability is to system availability. This flaw affects QEMU versions prior to 7.0.0.
A DMA reentrancy issue was found in the USB EHCI controller emulation of QEMU. EHCI does not verify if the Buffer Pointer overlaps with its MMIO region when it transfers the USB packets. Crafted content may be written to the controller's registers and trigger undesirable actions (such as reset) while the device is still transferring packets. This can ultimately lead to a use-after-free issue. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition, or potentially execute arbitrary code within the context of the QEMU process on the host. This flaw affects QEMU versions before 7.0.0.
A flaw was found in the QXL display device emulation in QEMU. An integer overflow in the cursor_alloc() function can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. This flaw allows a malicious privileged guest user to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.
A flaw was found in the QXL display device emulation in QEMU. A double fetch of guest controlled values `cursor->header.width` and `cursor->header.height` can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. A malicious privileged guest user could use this flaw to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.
It was discovered that the update for the virt:rhel module in the RHSA-2020:4676 (https://access.redhat.com/errata/RHSA-2020:4676) erratum released as part of Red Hat Enterprise Linux 8.3 failed to include the fix for the qemu-kvm component issue CVE-2020-10756, which was previously corrected in virt:rhel/qemu-kvm via erratum RHSA-2020:4059 (https://access.redhat.com/errata/RHSA-2020:4059). CVE-2021-20295 was assigned to that Red Hat specific security regression. For more details about the original security issue CVE-2020-10756, refer to bug 1835986 or the CVE page: https://access.redhat.com/security/cve/CVE-2020-10756.
A flaw was found in the QEMU implementation of VMWare's paravirtual RDMA device. This flaw allows a crafted guest driver to execute HW commands when shared buffers are not yet allocated, potentially leading to a use-after-free condition.
A flaw was found in the QEMU implementation of VMWare's paravirtual RDMA device. The issue occurs while handling a "PVRDMA_CMD_CREATE_MR" command due to improper memory remapping (mremap). This flaw allows a malicious guest to crash the QEMU process on the host. The highest threat from this vulnerability is to system availability.