Several memory leaks were found in the virtio vhost-user GPU device (vhost-user-gpu) of QEMU in versions up to and including 6.0. They exist in contrib/vhost-user-gpu/vhost-user-gpu.c and contrib/vhost-user-gpu/virgl.c due to improper release of memory (i.e., free) after effective lifetime.

A potential stack overflow via infinite loop issue was found in various NIC emulators of QEMU in versions up to and including 5.2.0. The issue occurs in loopback mode of a NIC wherein reentrant DMA checks get bypassed. A guest user/process may use this flaw to consume CPU cycles or crash the QEMU process on the host resulting in DoS scenario.

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.

The rw_vm function in usercopy.c in the 4GB split patch for the Linux kernel in Red Hat Enterprise Linux 4 does not perform proper bounds checking, which allows local users to cause a denial of service (crash).

Memory leak in the ip_options_get function in the Linux kernel before 2.6.10 allows local users to cause a denial of service (memory consumption) by repeatedly calling the ip_cmsg_send function.

Unknown vulnerability in Linux kernel 2.4.x, 2.5.x, and 2.6.x allows NFS clients to cause a denial of service via O_DIRECT.

The 64 bit ELF support in Linux kernel 2.6 before 2.6.10, on 64-bit architectures, does not properly check for overlapping VMA (virtual memory address) allocations, which allows local users to cause a denial of service (system crash) or execute arbitrary code via a crafted ELF or a.out file.

A regression error in the Red Hat Enterprise Linux 4 kernel 4GB/4GB split patch omits an "access check," which allows local users to cause a denial of service (crash).

Unknown vulnerability in the system call filtering code in the audit subsystem for Red Hat Enterprise Linux 3 allows local users to cause a denial of service (system crash) via unknown vectors.

Integer overflow in the vc_resize function in the Linux kernel 2.4 and 2.6 before 2.6.10 allows local users to cause a denial of service (kernel crash) via a short new screen value, which leads to a buffer overflow.

Integer overflow in the ip_options_get function in the Linux kernel before 2.6.10 allows local users to cause a denial of service (kernel crash) via a cmsg_len that contains a -1, which leads to a buffer overflow.

The binfmt functionality in the Linux kernel, when "memory overcommit" is enabled, allows local users to cause a denial of service (kernel oops) via a malformed a.out binary.

Linux kernel 2.4.x and 2.6.x for x86 allows local users to cause a denial of service (system crash), possibly via an infinite loop that triggers a signal handler with a certain sequence of fsave and frstor instructions, as originally demonstrated using a "crash.c" program.

Unknown vulnerability in the Linux kernel before 2.4.23, on the AMD AMD64 and Intel EM64T architectures, associated with "setting up TSS limits," allows local users to cause a denial of service (crash) and possibly execute arbitrary code.

pci_change_irq_level in hw/pci/pci.c in QEMU before 5.1.1 has a NULL pointer dereference because pci_get_bus() might not return a valid pointer.

Unspecified vulnerability in xscreensaver 4.12, and possibly other versions, allows attackers to cause xscreensaver to crash via unspecified vectors "while verifying the user-password."

QEMU (aka Quick Emulator), when built with the IDE disk and CD/DVD-ROM Emulator support, allows local guest OS privileged users to cause a denial of service (NULL pointer dereference and QEMU process crash) by flushing an empty CDROM device drive.

The tmpwatch utility in Red Hat Linux forks a new process for each directory level, which allows local users to cause a denial of service by creating deeply nested directories in /tmp or /var/tmp/.

The X font server xfs in Red Hat Linux 6.x allows an attacker to cause a denial of service via a malformed request.

Vulnerability in Mandrake Linux usermode package allows local users to to reboot or halt the system.

Linux gpm program allows local users to cause a denial of service by flooding the /dev/gpmctl device with STREAM sockets.

dumpreg in Red Hat Linux 5.1 opens /dev/mem with O_RDWR access, which allows local users to cause a denial of service (crash) by redirecting fd 1 (stdout) to the kernel.

netcfg 2.16-1 in Red Hat Linux 4.2 allows the Ethernet interface to be controlled by users on reboot when an option is set, which allows local users to cause a denial of service by shutting down the interface.

QEMU (aka Quick Emulator), when built with the VGA display emulator support, allows local guest OS privileged users to cause a denial of service (out-of-bounds read and QEMU process crash) via vectors involving display update.

The address_space_write_continue function in exec.c in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (out-of-bounds access and guest instance crash) by leveraging use of qemu_map_ram_ptr to access guest ram block area.

The dhcp_decode function in slirp/bootp.c in QEMU (aka Quick Emulator) allows local guest OS users to cause a denial of service (out-of-bounds read and QEMU process crash) via a crafted DHCP options string.

hw/rdma/rdma_backend.c in QEMU allows guest OS users to trigger out-of-bounds access via a PvrdmaSqWqe ring element with a large num_sge value.

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.

A flaw was found in NetworkManager in versions before 1.30.0. Setting match.path and activating a profile crashes NetworkManager. The highest threat from this vulnerability is to system availability.

The xattr file system code, as backported in Red Hat Enterprise Linux 3 on 64-bit systems, does not properly handle certain offsets, which allows local users to cause a denial of service (system crash) via certain actions on an ext3 file system with extended attributes enabled.

A flaw was found in the IPv4 Resource Reservation Protocol (RSVP) classifier in the Linux kernel. The xprt pointer may go beyond the linear part of the skb, leading to an out-of-bounds read in the `rsvp_classify` function. This issue may allow a local user to crash the system and cause a denial of service.

Unknown vulnerability in the Red Hat Enterprise Linux 4 kernel 4GB/4GB split patch, when running on x86 with the hugemem kernel, allows local users to cause a denial of service (crash).

In QEMU 4.1.0, an out-of-bounds read flaw was found in the ATI VGA implementation. It occurs in the ati_cursor_define() routine while handling MMIO write operations through the ati_mm_write() callback. A malicious guest could abuse this flaw to crash the QEMU process, resulting in a denial of service.

X fontserver xfs allows local users to cause a denial of service via malformed input to the server.

Linuxconf on Red Hat Linux 6.0 and earlier does not properly disable PAM-based access to the shutdown command, which could allow local users to cause a denial of service.

It was found that the Red Hat Enterprise Linux 8 kpatch update did not include the complete fix for CVE-2018-12207. A flaw was found in the way Intel CPUs handle inconsistency between, virtual to physical memory address translations in CPU's local cache and system software's Paging structure entries. A privileged guest user may use this flaw to induce a hardware Machine Check Error on the host processor, resulting in a severe DoS scenario by halting the processor. System software like OS OR Virtual Machine Monitor (VMM) use virtual memory system for storing program instructions and data in memory. Virtual Memory system uses Paging structures like Page Tables and Page Directories to manage system memory. The processor's Memory Management Unit (MMU) uses Paging structure entries to translate program's virtual memory addresses to physical memory addresses. The processor stores these address translations into its local cache buffer called - Translation Lookaside Buffer (TLB). TLB has two parts, one for instructions and other for data addresses. System software can modify its Paging structure entries to change address mappings OR certain attributes like page size etc. Upon such Paging structure alterations in memory, system software must invalidate the corresponding address translations in the processor's TLB cache. But before this TLB invalidation takes place, a privileged guest user may trigger an instruction fetch operation, which could use an already cached, but now invalid, virtual to physical address translation from Instruction TLB (ITLB). Thus accessing an invalid physical memory address and resulting in halting the processor due to the Machine Check Error (MCE) on Page Size Change.

It was found that Keycloak's Node.js adapter before version 4.8.3 did not properly verify the web token received from the server in its backchannel logout . An attacker with local access could use this to construct a malicious web token setting an NBF parameter that could prevent user access indefinitely.

Memory leak in the v9fs_write function in hw/9pfs/9p.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (memory consumption) by leveraging failure to free an IO vector.

Memory leak in the v9fs_link function in hw/9pfs/9p.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (memory consumption) via vectors involving a reference to the source fid object.

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.

Memory leak in the v9fs_xattrcreate function in hw/9pfs/9p.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (memory consumption and QEMU process crash) via a large number of Txattrcreate messages with the same fid number.

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.

QEMU (aka Quick Emulator) built with the ColdFire Fast Ethernet Controller emulator support is vulnerable to an infinite loop issue. It could occur while receiving packets in 'mcf_fec_receive'. A privileged user/process inside guest could use this issue to crash the QEMU process on the host leading to DoS.

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.

Quick Emulator (Qemu) built with the 'chardev' backend support is vulnerable to a use after free issue. It could occur while hotplug and unplugging the device in the guest. A guest user/process could use this flaw to crash a Qemu process on the host resulting in DoS.

Memory leak in hw/net/eepro100.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (memory consumption and QEMU process crash) by repeatedly unplugging an i8255x (PRO100) NIC device.

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 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 cirrus_do_copy function in hw/display/cirrus_vga.c in QEMU (aka Quick Emulator), when cirrus graphics mode is VGA, allows local guest OS privileged users to cause a denial of service (divide-by-zero error and QEMU process crash) via vectors involving blit pitch values.