An issue was discovered in Xen 4.14.x. There is a missing unlock in the XENMEM_acquire_resource error path. The RCU (Read, Copy, Update) mechanism is a synchronisation primitive. A buggy error path in the XENMEM_acquire_resource exits without releasing an RCU reference, which is conceptually similar to forgetting to unlock a spinlock. A buggy or malicious HVM stubdomain can cause an RCU reference to be leaked. This causes subsequent administration operations, (e.g., CPU offline) to livelock, resulting in a host Denial of Service. The buggy codepath has been present since Xen 4.12. Xen 4.14 and later are vulnerable to the DoS. The side effects are believed to be benign on Xen 4.12 and 4.13, but patches are provided nevertheless. The vulnerability can generally only be exploited by x86 HVM VMs, as these are generally the only type of VM that have a Qemu stubdomain. x86 PV and PVH domains, as well as ARM VMs, typically don't use a stubdomain. Only VMs using HVM stubdomains can exploit the vulnerability. VMs using PV stubdomains, or with emulators running in dom0, cannot exploit the vulnerability.

fdctrl_write_data in hw/block/fdc.c in QEMU 5.0.0 has a NULL pointer dereference via a NULL block pointer for the current drive.

The MSI-X MMIO support in hw/pci/msix.c in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (NULL pointer dereference and QEMU process crash) by leveraging failure to define the .write method.

A use after free vulnerability in ip_reass() in ip_input.c of libslirp 4.2.0 and prior releases allows crafted packets to cause a denial of service.

A use-after-free flaw was found in the MegaRAID emulator of QEMU. This issue occurs while processing SCSI I/O requests in the case of an error mptsas_free_request() that does not dequeue the request object 'req' from a pending requests queue. This flaw allows a privileged guest user to crash the QEMU process on the host, resulting in a denial of service. Versions between 2.10.0 and 5.2.0 are potentially affected.

Infinite Loop in zziplib v0.13.69 allows remote attackers to cause a denial of service via the return value "zzip_file_read" in the function "unzzip_cat_file".

Stack-based buffer overflow in hw/scsi/scsi-bus.c in QEMU, when built with SCSI-device emulation support, allows guest OS users with CAP_SYS_RAWIO permissions to cause a denial of service (instance crash) via an invalid opcode in a SCSI command descriptor block.

Buffer overflow in text-utils/colcrt.c in colcrt in util-linux before 2.27 allows local users to cause a denial of service (crash) via a crafted file, related to the page global variable.

Unspecified vulnerability in the Oracle VM VirtualBox component in Oracle Virtualization VirtualBox prior to 4.0.34, 4.1.42, 4.2.34, 4.3.32, and 5.0.8, when using a Windows guest, allows local users to affect availability via unknown vectors related to Core.

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)

The libevt_record_values_read_event() function in libevt_record_values.c in libevt before 2018-03-17 does not properly check for out-of-bounds values of user SID data size, strings size, or data size. NOTE: the vendor has disputed this as described in libyal/libevt issue 5 on GitHub

usb_8dev_start_xmit in drivers/net/can/usb/usb_8dev.c in the Linux kernel through 5.17.1 has a double free.

The bmexec_trans function in kwset.c in grep 2.19 through 2.21 allows local users to cause a denial of service (out-of-bounds heap read and crash) via crafted input when using the -F option.

Unspecified vulnerability in the Oracle VM VirtualBox component in Oracle Virtualization VirtualBox prior to 3.2.26, 4.0.28, 4.1.36, and 4.2.28 allows local users to affect availability via unknown vectors related to Core, a different vulnerability than CVE-2015-0377.

mcba_usb_start_xmit in drivers/net/can/usb/mcba_usb.c in the Linux kernel through 5.17.1 has a double free.

The sd2_parse_rsrc_fork function in sd2.c in libsndfile allows attackers to have unspecified impact via vectors related to a (1) map offset or (2) rsrc marker, which triggers an out-of-bounds read.

In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer size and source character limit, as demonstrated by an invalid write access (buffer overflow).

In Qemu 3.0.0, lsi_do_msgin in hw/scsi/lsi53c895a.c allows out-of-bounds access by triggering an invalid msg_len value.

D-Bus 1.3.0 through 1.6.x before 1.6.26, 1.8.x before 1.8.10, and 1.9.x before 1.9.2 allows local users to cause a denial of service (prevention of new connections and connection drop) by queuing the maximum number of file descriptors. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-3636.1.

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.

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

An issue was discovered in Xen through 4.14.x. A guest may access xenstore paths via absolute paths containing a full pathname, or via a relative path, which implicitly includes /local/domain/$DOMID for their own domain id. Management tools must access paths in guests' namespaces, necessarily using absolute paths. oxenstored imposes a pathname limit that is applied solely to the relative or absolute path specified by the client. Therefore, a guest can create paths in its own namespace which are too long for management tools to access. Depending on the toolstack in use, a malicious guest administrator might cause some management tools and debugging operations to fail. For example, a guest administrator can cause "xenstore-ls -r" to fail. However, a guest administrator cannot prevent the host administrator from tearing down the domain. All systems using oxenstored are vulnerable. Building and using oxenstored is the default in the upstream Xen distribution, if the Ocaml compiler is available. Systems using C xenstored are not vulnerable.

NLnet Labs Unbound, up to and including version 1.12.0, and NLnet Labs NSD, up to and including version 4.3.3, contain a local vulnerability that would allow for a local symlink attack. When writing the PID file, Unbound and NSD create the file if it is not there, or open an existing file for writing. In case the file was already present, they would follow symlinks if the file happened to be a symlink instead of a regular file. An additional chown of the file would then take place after it was written, making the user Unbound/NSD is supposed to run as the new owner of the file. If an attacker has local access to the user Unbound/NSD runs as, she could create a symlink in place of the PID file pointing to a file that she would like to erase. If then Unbound/NSD is killed and the PID file is not cleared, upon restarting with root privileges, Unbound/NSD will rewrite any file pointed at by the symlink. This is a local vulnerability that could create a Denial of Service of the system Unbound/NSD is running on. It requires an attacker having access to the limited permission user Unbound/NSD runs as and point through the symlink to a critical file on the system.

A stack overflow via an infinite recursion vulnerability was found in the eepro100 i8255x device emulator of QEMU. This issue occurs while processing controller commands due to a DMA reentry issue. This flaw allows a guest user or process to consume CPU cycles or crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

An infinite loop flaw was found in the e1000 NIC emulator of the QEMU. This issue occurs while processing transmits (tx) descriptors in process_tx_desc if various descriptor fields are initialized with invalid values. This flaw allows a guest to consume CPU cycles on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

The (1) qemuDomainMigratePerform and (2) qemuDomainMigrateFinish2 functions in qemu/qemu_driver.c in libvirt do not unlock the domain when an ACL check fails, which allow local users to cause a denial of service via unspecified vectors.

A vulnerability was found in Linux Kernel where in the spk_ttyio_receive_buf2() function, it would dereference spk_ttyio_synth without checking whether it is NULL or not, and may lead to a NULL-ptr deref crash.

Various memory and file descriptor leaks were found in apt-python files python/arfile.cc, python/tag.cc, python/tarfile.cc, aka GHSL-2020-170. This issue affects: python-apt 1.1.0~beta1 versions prior to 1.1.0~beta1ubuntu0.16.04.10; 1.6.5ubuntu0 versions prior to 1.6.5ubuntu0.4; 2.0.0ubuntu0 versions prior to 2.0.0ubuntu0.20.04.2; 2.1.3ubuntu1 versions prior to 2.1.3ubuntu1.1;

Use-after-free vulnerability in hw/pci/pcie.c in QEMU (aka Quick Emulator) allows local guest OS users to cause a denial of service (QEMU instance crash) via hotplug and hotunplug operations of Virtio block devices.

The dbus-daemon in D-Bus before 1.6.24 and 1.8.x before 1.8.8 does not properly close old connections, which allows local users to cause a denial of service (incomplete connection consumption and prevention of new connections) via a large number of incomplete connections.

dbus 1.3.0 before 1.6.22 and 1.8.x before 1.8.6 allows local users to cause a denial of service (disconnect) via a certain sequence of crafted messages that cause the dbus-daemon to forward a message containing an invalid file descriptor.

The sosendto function in slirp/udp.c in QEMU before 2.1.2 allows local users to cause a denial of service (NULL pointer dereference) by sending a udp packet with a value of 0 in the source port and address, which triggers access of an uninitialized socket.

If the attacker manages to create files in the directory used to collect log files in supportutils before version 3.1-5.7.1 (e.g. with CVE-2018-19638) he can kill arbitrary processes on the local machine.

Vulnerability in the Oracle VM VirtualBox component of Oracle Virtualization (subcomponent: Core). Supported versions that are affected are Prior to 5.2.32 and prior to 6.0.10. Easily exploitable vulnerability allows low privileged attacker with logon to the infrastructure where Oracle VM VirtualBox executes to compromise Oracle VM VirtualBox. Successful attacks of this vulnerability can result in unauthorized ability to cause a partial denial of service (partial DOS) of Oracle VM VirtualBox. CVSS 3.0 Base Score 3.3 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L).

Vulnerability in the Oracle VM VirtualBox component of Oracle Virtualization (subcomponent: Core). Supported versions that are affected are Prior to 5.2.32 and prior to 6.0.10. Easily exploitable vulnerability allows low privileged attacker with logon to the infrastructure where Oracle VM VirtualBox executes to compromise Oracle VM VirtualBox. Successful attacks of this vulnerability can result in unauthorized ability to cause a partial denial of service (partial DOS) of Oracle VM VirtualBox. CVSS 3.0 Base Score 3.3 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L).

The start_authentication function in lightdm-gtk-greeter.c in LightDM GTK+ Greeter before 1.7.1 does not properly handle the return value from the lightdm_greeter_get_authentication_user function, which allows local users to cause a denial of service (NULL pointer dereference) via an empty username.

The bus_connections_check_reply function in config-parser.c in D-Bus before 1.6.24 and 1.8.x before 1.8.8 allows local users to cause a denial of service (CPU consumption) via a large number of method calls.

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

dbus 1.3.0 before 1.6.22 and 1.8.x before 1.8.6, when running on Linux 2.6.37-rc4 or later, allows local users to cause a denial of service (system-bus disconnect of other services or applications) by sending a message containing a file descriptor, then exceeding the maximum recursion depth before the initial message is forwarded.

D-Bus 1.3.0 through 1.6.x before 1.6.24 and 1.8.x before 1.8.8 does not properly close connections for processes that have terminated, which allows local users to cause a denial of service via a D-bus message containing a D-Bus connection file descriptor.

QEMU 0.8.2 allows local users to halt a virtual machine by executing the icebp instruction.

A PV guest could DoS Xen while unmapping a grant To address XSA-380, reference counting was introduced for grant mappings for the case where a PV guest would have the IOMMU enabled. PV guests can request two forms of mappings. When both are in use for any individual mapping, unmapping of such a mapping can be requested in two steps. The reference count for such a mapping would then mistakenly be decremented twice. Underflow of the counters gets detected, resulting in the triggering of a hypervisor bug check.

An issue was discovered in Xen through 4.14.x. When a Xenstore watch fires, the xenstore client that registered the watch will receive a Xenstore message containing the path of the modified Xenstore entry that triggered the watch, and the tag that was specified when registering the watch. Any communication with xenstored is done via Xenstore messages, consisting of a message header and the payload. The payload length is limited to 4096 bytes. Any request to xenstored resulting in a response with a payload longer than 4096 bytes will result in an error. When registering a watch, the payload length limit applies to the combined length of the watched path and the specified tag. Because watches for a specific path are also triggered for all nodes below that path, the payload of a watch event message can be longer than the payload needed to register the watch. A malicious guest that registers a watch using a very large tag (i.e., with a registration operation payload length close to the 4096 byte limit) can cause the generation of watch events with a payload length larger than 4096 bytes, by writing to Xenstore entries below the watched path. This will result in an error condition in xenstored. This error can result in a NULL pointer dereference, leading to a crash of xenstored. A malicious guest administrator can cause xenstored to crash, leading to a denial of service. Following a xenstored crash, domains may continue to run, but management operations will be impossible. Only C xenstored is affected, oxenstored is not affected.

A flaw was found in pacemaker up to and including version 2.0.1. An insufficient verification inflicted preference of uncontrolled processes can lead to DoS

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.

The iconv function in the GNU C Library (aka glibc or libc6) 2.32 and earlier, when processing invalid multi-byte input sequences in IBM1364, IBM1371, IBM1388, IBM1390, and IBM1399 encodings, fails to advance the input state, which could lead to an infinite loop in applications, resulting in a denial of service, a different vulnerability from CVE-2016-10228.

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.

An issue was discovered in Xen through 4.10.x. One of the fixes in XSA-260 added some safety checks to help prevent Xen livelocking with debug exceptions. Unfortunately, due to an oversight, at least one of these safety checks can be triggered by a guest. A malicious PV guest can crash Xen, leading to a Denial of Service. All Xen systems which have applied the XSA-260 fix are vulnerable. Only x86 systems are vulnerable. ARM systems are not vulnerable. Only x86 PV guests can exploit the vulnerability. x86 HVM and PVH guests cannot exploit the vulnerability. An attacker needs to be able to control hardware debugging facilities to exploit the vulnerability, but such permissions are typically available to unprivileged users.

Qemu has integer overflows because IOReadHandler and its associated functions use a signed integer data type for a size value.