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

The manager_dispatch_notify_fd function in systemd allows local users to cause a denial of service (system hang) via a zero-length message received over a notify socket, which causes an error to be returned and the notification handler to be disabled.

The pcnet_rdra_addr function in hw/net/pcnet.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) by setting the (1) receive or (2) transmit descriptor ring length to 0.

A certain Fedora patch for the utrace subsystem in the Linux kernel before 2.6.26.5-28 on Fedora 8, and before 2.6.26.5-45 on Fedora 9, allows local users to cause a denial of service (NULL pointer dereference and system crash or hang) via a call to the utrace_control function.

fs/fcntl.c in the "aufs 3.2.x+setfl-debian" patch in the linux-image package 3.2.0-4 (kernel 3.2.81-1) in Debian wheezy mishandles F_SETFL fcntl calls on directories, which allows local users to cause a denial of service (NULL pointer dereference and system crash) via standard filesystem operations, as demonstrated by scp from an AUFS filesystem.

Off-by-one error in the iov_iter_advance function in mm/filemap.c in the Linux kernel before 2.6.27-rc2 allows local users to cause a denial of service (system crash) via a certain sequence of file I/O operations with readv and writev, as demonstrated by testcases/kernel/fs/ftest/ftest03 from the Linux Test Project.

The shmem_delete_inode function in mm/shmem.c in the tmpfs implementation in the Linux kernel before 2.6.26.1 allows local users to cause a denial of service (system crash) via a certain sequence of file create, remove, and overwrite operations, as demonstrated by the insserv program, related to allocation of "useless pages" and improper maintenance of the i_blocks count.

The virtqueue_pop function in hw/virtio/virtio.c in QEMU allows local guest OS administrators to cause a denial of service (memory consumption and QEMU process crash) by submitting requests without waiting for completion.

NVIDIA GPU Display Driver for Windows and Linux contains a vulnerability in the kernel mode layer, where an unprivileged user can cause a null-pointer dereference, which may lead to denial of service.

NVIDIA GPU Display Driver for Windows and Linux contains a vulnerability in the kernel mode layer, where a local user with basic capabilities can cause a null-pointer dereference, which may lead to denial of service.

Double free vulnerability in the utrace support in the Linux kernel, probably 2.6.18, in Red Hat Enterprise Linux (RHEL) 5 and Fedora Core 6 (FC6) allows local users to cause a denial of service (oops), as demonstrated by a crash when running the GNU GDB testsuite, a different vulnerability than CVE-2008-2365.

Integer overflow in the sctp_getsockopt_local_addrs_old function in net/sctp/socket.c in the Stream Control Transmission Protocol (sctp) functionality in the Linux kernel before 2.6.25.9 allows local users to cause a denial of service (resource consumption and system outage) via vectors involving a large addr_num field in an sctp_getaddrs_old data structure.

The parse_dos_extended function in partitions/dos.c in the libblkid library in util-linux allows physically proximate attackers to cause a denial of service (memory consumption) via a crafted MSDOS partition table with an extended partition boot record at zero offset.

The vmsvga_fifo_run function in hw/display/vmware_vga.c in QEMU allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via a VGA command.

The mptsas_fetch_requests function in hw/scsi/mptsas.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (infinite loop, and CPU consumption or QEMU process crash) via vectors involving s->state.

The (1) real_lookup and (2) __lookup_hash functions in fs/namei.c in the vfs implementation in the Linux kernel before 2.6.25.15 do not prevent creation of a child dentry for a deleted (aka S_DEAD) directory, which allows local users to cause a denial of service ("overflow" of the UBIFS orphan area) via a series of attempted file creations within deleted directories.

Linux kernel before version 4.16-rc7 is vulnerable to a null pointer dereference in dccp_write_xmit() function in net/dccp/output.c in that allows a local user to cause a denial of service by a number of certain crafted system calls.

The ehci_advance_state function in hw/usb/hcd-ehci.c in QEMU allows local guest OS administrators to cause a denial of service (infinite loop and CPU consumption) via a circular split isochronous transfer descriptor (siTD) list, a related issue to CVE-2015-8558.

Comix 3.6.4 creates temporary directories with predictable names, which allows local users to cause an unspecified denial of service.

Linux kernel 2.6.18, and possibly other versions, when running on AMD64 architectures, allows local users to cause a denial of service (crash) via certain ptrace calls.

QEMU, when built with the Pseudo Random Number Generator (PRNG) back-end support, allows local guest OS users to cause a denial of service (process crash) via an entropy request, which triggers arbitrary stack based allocation and memory corruption.

Memory leak in hw/watchdog/wdt_i6300esb.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 ehci_process_itd function in hw/usb/hcd-ehci.c in QEMU allows local guest OS administrators to cause a denial of service (infinite loop and CPU consumption) via a circular isochronous transfer descriptor (iTD) list.

The eepro100 emulator in QEMU qemu-kvm blank allows local guest users to cause a denial of service (application crash and infinite loop) via vectors involving the command block list.

net/sctp/sm_sideeffect.c in the Linux kernel before 4.3 does not properly manage the relationship between a lock and a socket, which allows local users to cause a denial of service (deadlock) via a crafted sctp_accept call.

QEMU (aka Quick Emulator) built with the Rocker switch emulation support is vulnerable to an off-by-one error. It happens while processing transmit (tx) descriptors in 'tx_consume' routine, if a descriptor was to have more than allowed (ROCKER_TX_FRAGS_MAX=16) fragments. A privileged user inside guest could use this flaw to cause memory leakage on the host or crash the QEMU process instance resulting in DoS issue.

Stack-based buffer overflow in the megasas_ctrl_get_info function in QEMU, when built with SCSI MegaRAID SAS HBA emulation support, allows local guest users to cause a denial of service (QEMU instance crash) via a crafted SCSI controller CTRL_GET_INFO command.

A NULL pointer dereference issue was found in the block mirror layer of QEMU in versions prior to 6.2.0. The `self` pointer is dereferenced in mirror_wait_on_conflicts() without ensuring that it's not NULL. A malicious unprivileged user within the guest could use this flaw to crash the QEMU process on the host when writing data reaches the threshold of mirroring node.

The __rds_conn_create function in net/rds/connection.c in the Linux kernel through 4.2.3 allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact by using a socket that was not properly bound.

The usbvision driver in the Linux kernel package 3.10.0-123.20.1.el7 through 3.10.0-229.14.1.el7 in Red Hat Enterprise Linux (RHEL) 7.1 allows physically proximate attackers to cause a denial of service (panic) via a nonzero bInterfaceNumber value in a USB device descriptor.

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.

fs/direct-io.c in the dio subsystem in the Linux kernel before 2.6.23 does not properly zero out the dio struct, which allows local users to cause a denial of service (OOPS), as demonstrated by a certain fio test.

Red Hat Enterprise Linux 5 and Fedora install the Bind /etc/rndc.key file with world-readable permissions, which allows local users to perform unauthorized named commands, such as causing a denial of service by stopping named.

In ImfChromaticities.cpp routine RGBtoXYZ(), there are some division operations such as `float Z = (1 - chroma.white.x - chroma.white.y) * Y / chroma.white.y;` and `chroma.green.y * (X + Z))) / d;` but the divisor is not checked for a 0 value. A specially crafted file could trigger a divide-by-zero condition which could affect the availability of programs linked with OpenEXR.

An off-by-one error was found in the SCSI device emulation in QEMU. It could occur while processing MODE SELECT commands in mode_sense_page() if the 'page' argument was set to MODE_PAGE_ALLS (0x3f). A malicious guest could use this flaw to potentially crash QEMU, resulting in a denial of service condition.

The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a denial of service (host OS panic or hang) by triggering many #AC (aka Alignment Check) exceptions, related to svm.c and vmx.c.

The ping_unhash function in net/ipv4/ping.c in the Linux kernel before 4.0.3 does not initialize a certain list data structure during an unhash operation, which allows local users to gain privileges or cause a denial of service (use-after-free and system crash) by leveraging the ability to make a SOCK_DGRAM socket system call for the IPPROTO_ICMP or IPPROTO_ICMPV6 protocol, and then making a connect system call after a disconnect.

Memory leak in the Red Hat Content Accelerator kernel patch in Red Hat Enterprise Linux (RHEL) 4 and 5 allows local users to cause a denial of service (memory consumption) via a large number of open requests involving O_ATOMICLOOKUP.

A flaw was found in the Linux kernel netfilter implementation in versions prior to 5.5-rc7. A user with root (CAP_SYS_ADMIN) access is able to panic the system when issuing netfilter netflow commands.

QEMU, as used in Xen 3.3.x through 4.5.x, does not properly restrict access to PCI command registers, which might allow local HVM guest users to cause a denial of service (non-maskable interrupt and host crash) by disabling the (1) memory or (2) I/O decoding for a PCI Express device and then accessing the device, which triggers an Unsupported Request (UR) response.

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.

Linux kernel before 2.4.21 allows local users to cause a denial of service (kernel panic) via asynchronous input or output on a FIFO special file.

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 getifaddrs function in GNU libc (glibc) 2.2.4 and earlier allows local users to cause a denial of service by sending spoofed messages as other users to the kernel netlink interface.

It was found that the issue for security flaw CVE-2019-3805 appeared again in a further version of JBoss Enterprise Application Platform - Continuous Delivery (EAP-CD) introducing regression. An attacker could exploit this by modifying the PID file in /var/run/jboss-eap/ allowing the init.d script to terminate any process as root.

Quick emulator (Qemu) built with the Cirrus CLGD 54xx VGA Emulator support is vulnerable to a divide by zero issue. It could occur while copying VGA data when cirrus graphics mode was set to be VGA. A privileged user inside guest could use this flaw to crash the Qemu process instance on the host, resulting in DoS.

The sysfs_readdir function in the Linux kernel 2.6, as used in Red Hat Enterprise Linux (RHEL) 4.5 and other distributions, allows users to cause a denial of service (kernel OOPS) by dereferencing a null pointer to an inode in a dentry.

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

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.