arch/x86/kvm/x86.c in the Linux kernel before 4.4 does not reset the PIT counter values during state restoration, which allows guest OS users to cause a denial of service (divide-by-zero error and host OS crash) via a zero value, related to the kvm_vm_ioctl_set_pit and kvm_vm_ioctl_set_pit2 functions.

The slirp_smb function in net/slirp.c in QEMU 2.3.0 and earlier creates temporary files with predictable names, which allows local users to cause a denial of service (instantiation failure) by creating /tmp/qemu-smb.*-* files before the program.

In X.Org Server (aka xserver and xorg-server) before 1.19.4, an attacker authenticated to an X server with the X shared memory extension enabled can cause aborts of the X server or replace shared memory segments of other X clients in the same session.

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.

Memory leak in hw/9pfs/9p.c in QEMU (aka Quick Emulator) allows local privileged guest OS users to cause a denial of service (host memory consumption and possibly QEMU process crash) by leveraging a missing cleanup operation in FileOperations.

Memory leak in hw/9pfs/9p-handle.c in QEMU (aka Quick Emulator) allows local privileged guest OS users to cause a denial of service (host memory consumption and possibly QEMU process crash) by leveraging a missing cleanup operation in the handle backend.

Memory leak in hw/9pfs/9p-proxy.c in QEMU (aka Quick Emulator) allows local privileged guest OS users to cause a denial of service (host memory consumption and possibly QEMU process crash) by leveraging a missing cleanup operation in the proxy backend.

The fix for XSA-365 includes initialization of pointers such that subsequent cleanup code wouldn't use uninitialized or stale values. This initialization went too far and may under certain conditions also overwrite pointers which are in need of cleaning up. The lack of cleanup would result in leaking persistent grants. The leak in turn would prevent fully cleaning up after a respective guest has died, leaving around zombie domains. All Linux versions having the fix for XSA-365 applied are vulnerable. XSA-365 was classified to affect versions back to at least 3.11.

Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Client programs). Supported versions that are affected are 5.5.61 and prior, 5.6.41 and prior, 5.7.23 and prior and 8.0.12 and prior. Difficult to exploit vulnerability allows high privileged attacker with logon to the infrastructure where MySQL Server executes to compromise MySQL Server. While the vulnerability is in MySQL Server, attacks may significantly impact additional products. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.0 Base Score 5.3 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:N/A:H).

Guest can force Linux netback driver to hog large amounts of kernel memory T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Incoming data packets for a guest in the Linux kernel's netback driver are buffered until the guest is ready to process them. There are some measures taken for avoiding to pile up too much data, but those can be bypassed by the guest: There is a timeout how long the client side of an interface can stop consuming new packets before it is assumed to have stalled, but this timeout is rather long (60 seconds by default). Using a UDP connection on a fast interface can easily accumulate gigabytes of data in that time. (CVE-2021-28715) The timeout could even never trigger if the guest manages to have only one free slot in its RX queue ring page and the next package would require more than one free slot, which may be the case when using GSO, XDP, or software hashing. (CVE-2021-28714)

A race condition was discovered in get_old_root in fs/btrfs/ctree.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (BUG) because of a lack of locking on an extent buffer before a cloning operation, aka CID-dbcc7d57bffc.

Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Client programs). Supported versions that are affected are 5.5.59 and prior, 5.6.39 and prior and 5.7.21 and prior. Difficult to exploit vulnerability allows high privileged attacker with logon to the infrastructure where MySQL Server executes to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.0 Base Score 4.1 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H).

Rogue backends can cause DoS of guests via high frequency events T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Xen offers the ability to run PV backends in regular unprivileged guests, typically referred to as "driver domains". Running PV backends in driver domains has one primary security advantage: if a driver domain gets compromised, it doesn't have the privileges to take over the system. However, a malicious driver domain could try to attack other guests via sending events at a high frequency leading to a Denial of Service in the guest due to trying to service interrupts for elongated amounts of time. There are three affected backends: * blkfront patch 1, CVE-2021-28711 * netfront patch 2, CVE-2021-28712 * hvc_xen (console) patch 3, CVE-2021-28713

GNU Tar through 1.30, when --sparse is used, mishandles file shrinkage during read access, which allows local users to cause a denial of service (infinite read loop in sparse_dump_region in sparse.c) by modifying a file that is supposed to be archived by a different user's process (e.g., a system backup running as root).

An issue was discovered in the Linux kernel through 5.11.3, as used with Xen PV. A certain part of the netback driver lacks necessary treatment of errors such as failed memory allocations (as a result of changes to the handling of grant mapping errors). A host OS denial of service may occur during misbehavior of a networking frontend driver. NOTE: this issue exists because of an incomplete fix for CVE-2021-26931.

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.

Rogue backends can cause DoS of guests via high frequency events T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Xen offers the ability to run PV backends in regular unprivileged guests, typically referred to as "driver domains". Running PV backends in driver domains has one primary security advantage: if a driver domain gets compromised, it doesn't have the privileges to take over the system. However, a malicious driver domain could try to attack other guests via sending events at a high frequency leading to a Denial of Service in the guest due to trying to service interrupts for elongated amounts of time. There are three affected backends: * blkfront patch 1, CVE-2021-28711 * netfront patch 2, CVE-2021-28712 * hvc_xen (console) patch 3, CVE-2021-28713

Rogue backends can cause DoS of guests via high frequency events T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Xen offers the ability to run PV backends in regular unprivileged guests, typically referred to as "driver domains". Running PV backends in driver domains has one primary security advantage: if a driver domain gets compromised, it doesn't have the privileges to take over the system. However, a malicious driver domain could try to attack other guests via sending events at a high frequency leading to a Denial of Service in the guest due to trying to service interrupts for elongated amounts of time. There are three affected backends: * blkfront patch 1, CVE-2021-28711 * netfront patch 2, CVE-2021-28712 * hvc_xen (console) patch 3, CVE-2021-28713

It was discovered systemd does not correctly check the content of PIDFile files before using it to kill processes. When a service is run from an unprivileged user (e.g. User field set in the service file), a local attacker who is able to write to the PIDFile of the mentioned service may use this flaw to trick systemd into killing other services and/or privileged processes. Versions before v237 are vulnerable.

A memory leak in rsyslog before 5.7.6 was found in the way deamon processed log messages are logged when $RepeatedMsgReduction was enabled. A local attacker could use this flaw to cause a denial of the rsyslogd daemon service by crashing the service via a sequence of repeated log messages sent within short periods of time.

arch/x86/x86_emulate/x86_emulate.c in Xen 3.2.1 through 4.4.x does not properly check privileges, which allows local HVM guest users to gain privileges or cause a denial of service (crash) via a crafted (1) CALL, (2) JMP, (3) RETF, (4) LCALL, (5) LJMP, or (6) LRET far branch instruction.

Guest can force Linux netback driver to hog large amounts of kernel memory T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Incoming data packets for a guest in the Linux kernel's netback driver are buffered until the guest is ready to process them. There are some measures taken for avoiding to pile up too much data, but those can be bypassed by the guest: There is a timeout how long the client side of an interface can stop consuming new packets before it is assumed to have stalled, but this timeout is rather long (60 seconds by default). Using a UDP connection on a fast interface can easily accumulate gigabytes of data in that time. (CVE-2021-28715) The timeout could even never trigger if the guest manages to have only one free slot in its RX queue ring page and the next package would require more than one free slot, which may be the case when using GSO, XDP, or software hashing. (CVE-2021-28714)

arch/x86/kvm/emulate.c in the KVM subsystem in the Linux kernel through 3.17.2 does not properly perform RIP changes, which allows guest OS users to cause a denial of service (guest OS crash) via a crafted application.

The qcow2_open function in the (block/qcow2.c) in QEMU before 1.7.2 and 2.x before 2.0.0 allows local users to cause a denial of service (NULL pointer dereference) via a crafted image which causes an error, related to the initialization of the snapshot_offset and nb_snapshots fields.

An issue was discovered in Xen through 4.14.x. Xenstored and guests communicate via a shared memory page using a specific protocol. When a guest violates this protocol, xenstored will drop the connection to that guest. Unfortunately, this is done by just removing the guest from xenstored's internal management, resulting in the same actions as if the guest had been destroyed, including sending an @releaseDomain event. @releaseDomain events do not say that the guest has been removed. All watchers of this event must look at the states of all guests to find the guest that has been removed. When an @releaseDomain is generated due to a domain xenstored protocol violation, because the guest is still running, the watchers will not react. Later, when the guest is actually destroyed, xenstored will no longer have it stored in its internal data base, so no further @releaseDomain event will be sent. This can lead to a zombie domain; memory mappings of that guest's memory will not be removed, due to the missing event. This zombie domain will be cleaned up only after another domain is destroyed, as that will trigger another @releaseDomain event. If the device model of the guest that violated the Xenstore protocol is running in a stub-domain, a use-after-free case could happen in xenstored, after having removed the guest from its internal data base, possibly resulting in a crash of xenstored. A malicious guest can block resources of the host for a period after its own death. Guests with a stub domain device model can eventually crash xenstored, resulting in a more serious denial of service (the prevention of any further domain management operations). Only the C variant of Xenstore is affected; the Ocaml variant is not affected. Only HVM guests with a stubdom device model can cause a serious DoS.

The nameserver caching daemon (nscd) in the GNU C Library (aka glibc or libc6) 2.29 through 2.33, when processing a request for netgroup lookup, may crash due to a double-free, potentially resulting in degraded service or Denial of Service on the local system. This is related to netgroupcache.c.

An issue was discovered in the Linux kernel 3.2 through 5.10.16, as used by Xen. Grant mapping operations often occur in batch hypercalls, where a number of operations are done in a single hypercall, the success or failure of each one is reported to the backend driver, and the backend driver then loops over the results, performing follow-up actions based on the success or failure of each operation. Unfortunately, when running in PV mode, the Linux backend drivers mishandle this: Some errors are ignored, effectively implying their success from the success of related batch elements. In other cases, errors resulting from one batch element lead to further batch elements not being inspected, and hence successful ones to not be possible to properly unmap upon error recovery. Only systems with Linux backends running in PV mode are vulnerable. Linux backends run in HVM / PVH modes are not vulnerable. This affects arch/*/xen/p2m.c and drivers/xen/gntdev.c.

An issue was discovered in the Linux kernel 2.6.39 through 5.10.16, as used in Xen. Block, net, and SCSI backends consider certain errors a plain bug, deliberately causing a kernel crash. For errors potentially being at least under the influence of guests (such as out of memory conditions), it isn't correct to assume a plain bug. Memory allocations potentially causing such crashes occur only when Linux is running in PV mode, though. This affects drivers/block/xen-blkback/blkback.c and drivers/xen/xen-scsiback.c.

QEMU (aka Quick Emulator), when built with the e1000e NIC emulation support, allows local guest OS privileged users to cause a denial of service (infinite loop) via vectors related to setting the initial receive / transmit descriptor head (TDH/RDH) outside the allocated descriptor buffer.

QEMU (aka Quick Emulator) before 2.9.0, when built with the USB OHCI Emulation support, allows local guest OS users to cause a denial of service (infinite loop) by leveraging an incorrect return value, a different vulnerability than CVE-2017-6505.

QEMU (aka Quick Emulator), when built with MegaRAID SAS 8708EM2 Host Bus Adapter emulation support, allows local guest OS privileged users to cause a denial of service (NULL pointer dereference and QEMU process crash) via vectors involving megasas command processing.

QEMU (aka Quick Emulator), when built with USB xHCI controller emulator support, allows local guest OS privileged users to cause a denial of service (infinite recursive call) via vectors involving control transfer descriptors sequencing.

Memory leak in QEMU (aka Quick Emulator), when built with IDE AHCI Emulation support, allows local guest OS privileged users to cause a denial of service (memory consumption) by repeatedly hot-unplugging the AHCI device.

hw/scsi/vmw_pvscsi.c in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (infinite loop and CPU consumption) via the message ring page count.

Memory leak in the v9fs_device_unrealize_common function in hw/9pfs/9p.c in QEMU (aka Quick Emulator) allows local privileged guest OS users to cause a denial of service (host memory consumption and possibly QEMU process crash) via vectors involving the order of resource cleanup.

Memory leak in the v9fs_list_xattr function in hw/9pfs/9p-xattr.c in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (memory consumption) via vectors involving the orig_value variable.

Memory leak in the keyboard input event handlers support in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (host memory consumption) by rapidly generating large keyboard events.

Quick Emulator (Qemu) built with the Virtio GPU Device emulator support is vulnerable to a memory leakage issue. It could occur while destroying gpu resource object in 'virtio_gpu_resource_destroy'. A guest user/process could use this flaw to leak host memory bytes, resulting in DoS for a host.

The ohci_service_ed_list function in hw/usb/hcd-ohci.c in QEMU (aka Quick Emulator) before 2.9.0 allows local guest OS users to cause a denial of service (infinite loop) via vectors involving the number of link endpoint list descriptors, a different vulnerability than CVE-2017-9330.

Memory leak in the serial_exit_core function in hw/char/serial.c in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (host memory consumption and QEMU process crash) via a large number of device unplug operations.

Memory leak in the virgl_resource_attach_backing function in hw/display/virtio-gpu-3d.c in QEMU (aka Quick Emulator) allows local guest OS users to cause a denial of service (host memory consumption) via a large number of VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING commands.

Memory leak in hw/audio/ac97.c in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (host memory consumption and QEMU process crash) via a large number of device unplug operations.

The sdhci_sdma_transfer_multi_blocks function in hw/sd/sdhci.c in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (out-of-bounds heap access and crash) or execute arbitrary code on the QEMU host via vectors involving the data transfer length.

Memory leak in the megasas_handle_dcmd function in hw/scsi/megasas.c in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (host memory consumption) via MegaRAID Firmware Interface (MFI) commands with the sglist size set to a value over 2 Gb.

Memory leak in hw/audio/es1370.c in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (host memory consumption and QEMU process crash) via a large number of device unplug operations.

Memory leak in the virgl_cmd_resource_unref function in hw/display/virtio-gpu-3d.c in QEMU (aka Quick Emulator) allows local guest OS users to cause a denial of service (host memory consumption) via a large number of VIRTIO_GPU_CMD_RESOURCE_UNREF commands sent without detaching the backing storage beforehand.

Memory leak in the virtio_gpu_resource_attach_backing function in hw/display/virtio-gpu.c in QEMU (aka Quick Emulator) allows local guest OS users to cause a denial of service (host memory consumption) via a large number of VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING commands.

Xenstore: guests can let run xenstored out of memory T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Malicious guests can cause xenstored to allocate vast amounts of memory, eventually resulting in a Denial of Service (DoS) of xenstored. There are multiple ways how guests can cause large memory allocations in xenstored: - - by issuing new requests to xenstored without reading the responses, causing the responses to be buffered in memory - - by causing large number of watch events to be generated via setting up multiple xenstore watches and then e.g. deleting many xenstore nodes below the watched path - - by creating as many nodes as allowed with the maximum allowed size and path length in as many transactions as possible - - by accessing many nodes inside a transaction

x86/HVM pinned cache attributes mis-handling T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] To allow cachability control for HVM guests with passed through devices, an interface exists to explicitly override defaults which would otherwise be put in place. While not exposed to the affected guests themselves, the interface specifically exists for domains controlling such guests. This interface may therefore be used by not fully privileged entities, e.g. qemu running deprivileged in Dom0 or qemu running in a so called stub-domain. With this exposure it is an issue that - the number of the such controlled regions was unbounded (CVE-2022-42333), - installation and removal of such regions was not properly serialized (CVE-2022-42334).