Sequence of processor instructions leads to unexpected behavior for some Intel(R) Processors may allow an authenticated user to potentially enable escalation of privilege and/or information disclosure and/or denial of service via local access.

libffi requests an executable stack allowing attackers to more easily trigger arbitrary code execution by overwriting the stack. Please note that libffi is used by a number of other libraries. It was previously stated that this affects libffi version 3.2.1 but this appears to be incorrect. libffi prior to version 3.1 on 32 bit x86 systems was vulnerable, and upstream is believed to have fixed this issue in version 3.1.

A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "int_ctl" field, this issue could allow a malicious L1 to enable AVIC support (Advanced Virtual Interrupt Controller) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape. This flaw affects Linux kernel versions prior to 5.14-rc7.

A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "virt_ext" field, this issue could allow a malicious L1 to disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape.

A use-after-free in function hci_sock_bound_ioctl() of the Linux kernel HCI subsystem was found in the way user calls ioct HCIUNBLOCKADDR or other way triggers race condition of the call hci_unregister_dev() together with one of the calls hci_sock_blacklist_add(), hci_sock_blacklist_del(), hci_get_conn_info(), hci_get_auth_info(). A privileged local user could use this flaw to crash the system or escalate their privileges on the system. This flaw affects the Linux kernel versions prior to 5.13-rc5.

Format string vulnerability in the b43_request_firmware function in drivers/net/wireless/b43/main.c in the Broadcom B43 wireless driver in the Linux kernel through 3.9.4 allows local users to gain privileges by leveraging root access and including format string specifiers in an fwpostfix modprobe parameter, leading to improper construction of an error message.

In NTFS-3G versions < 2021.8.22, when a specially crafted NTFS inode is loaded in the function ntfs_inode_real_open, a heap buffer overflow can occur allowing for code execution and escalation of privileges.

kernel/module.c in the Linux kernel before 5.12.14 mishandles Signature Verification, aka CID-0c18f29aae7c. Without CONFIG_MODULE_SIG, verification that a kernel module is signed, for loading via init_module, does not occur for a module.sig_enforce=1 command-line argument.

An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service or gain privileges because of an incompatibility between Process Context Identifiers (PCID) and TLB flushes.

An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service or possibly gain privileges because of missing memory barriers in read-write unlock paths. The read-write unlock paths don't contain a memory barrier. On Arm, this means a processor is allowed to re-order the memory access with the preceding ones. In other words, the unlock may be seen by another processor before all the memory accesses within the "critical" section. As a consequence, it may be possible to have a writer executing a critical section at the same time as readers or another writer. In other words, many of the assumptions (e.g., a variable cannot be modified after a check) in the critical sections are not safe anymore. The read-write locks are used in hypercalls (such as grant-table ones), so a malicious guest could exploit the race. For instance, there is a small window where Xen can leak memory if XENMAPSPACE_grant_table is used concurrently. A malicious guest may be able to leak memory, or cause a hypervisor crash resulting in a Denial of Service (DoS). Information leak and privilege escalation cannot be excluded.

init_tmp in TeeJee.FileSystem.vala in Timeshift before 20.03 unsafely reuses a preexisting temporary directory in the predictable location /tmp/timeshift. It follows symlinks in this location or uses directories owned by unprivileged users. Because Timeshift also executes scripts under this location, an attacker can attempt to win a race condition to replace scripts created by Timeshift with attacker-controlled scripts. Upon success, an attacker-controlled script is executed with full root privileges. This logic is practically always triggered when Timeshift runs regardless of the command-line arguments used.

A crafted NTFS image can cause an out-of-bounds read in ntfs_runlists_merge_i in NTFS-3G < 2021.8.22.

In NTFS-3G versions < 2021.8.22, when a specially crafted NTFS inode pathname is supplied in an NTFS image a heap buffer overflow can occur resulting in memory disclosure, denial of service and even code execution.

A use-after-free vulnerability was found in the virtio-net device of QEMU. It could occur when the descriptor's address belongs to the non direct access region, due to num_buffers being set after the virtqueue elem has been unmapped. A malicious guest could use this flaw to crash QEMU, resulting in a denial of service condition, or potentially execute code on the host with the privileges of the QEMU process.

The fork implementation in the Linux kernel before 4.5 on s390 platforms mishandles the case of four page-table levels, which allows local users to cause a denial of service (system crash) or possibly have unspecified other impact via a crafted application, related to arch/s390/include/asm/mmu_context.h and arch/s390/include/asm/pgalloc.h.

Use-after-free vulnerability in hw/ide/ahci.c in QEMU, when built with IDE AHCI Emulation support, allows guest OS users to cause a denial of service (instance crash) or possibly execute arbitrary code via an invalid AHCI Native Command Queuing (NCQ) AIO command.

A flaw use-after-free in function sco_sock_sendmsg() of the Linux kernel HCI subsystem was found in the way user calls ioct UFFDIO_REGISTER or other way triggers race condition of the call sco_conn_del() together with the call sco_sock_sendmsg() with the expected controllable faulting memory page. A privileged local user could use this flaw to crash the system or escalate their privileges on the system.

Multiple integer overflows in the Elf parser (libelf) in Xen 4.2.x and earlier allow local guest administrators with certain permissions to have an unspecified impact via a crafted kernel.

Multiple unspecified vulnerabilities in the Elf parser (libelf) in Xen 4.2.x and earlier allow local guest administrators with certain permissions to have an unspecified impact via a crafted kernel, related to "other problems" that are not CVE-2013-2194 or CVE-2013-2195.

An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to cause a denial of service via degenerate chains of linear pagetables, because of an incorrect fix for CVE-2017-15595. "Linear pagetables" is a technique which involves either pointing a pagetable at itself, or to another pagetable of the same or higher level. Xen has limited support for linear pagetables: A page may either point to itself, or point to another pagetable of the same level (i.e., L2 to L2, L3 to L3, and so on). XSA-240 introduced an additional restriction that limited the "depth" of such chains by allowing pages to either *point to* other pages of the same level, or *be pointed to* by other pages of the same level, but not both. To implement this, we keep track of the number of outstanding times a page points to or is pointed to another page table, to prevent both from happening at the same time. Unfortunately, the original commit introducing this reset this count when resuming validation of a partially-validated pagetable, incorrectly dropping some "linear_pt_entry" counts. If an attacker could engineer such a situation to occur, they might be able to make loops or other arbitrary chains of linear pagetables, as described in XSA-240. A malicious or buggy PV guest may cause the hypervisor to crash, resulting in Denial of Service (DoS) affecting the entire host. Privilege escalation and information leaks cannot be excluded. All versions of Xen are vulnerable. Only x86 systems are affected. Arm systems are not affected. Only x86 PV guests can leverage the vulnerability. x86 HVM and PVH guests cannot leverage the vulnerability. Only systems which have enabled linear pagetables are vulnerable. Systems which have disabled linear pagetables, either by selecting CONFIG_PV_LINEAR_PT=n when building the hypervisor, or adding pv-linear-pt=false on the command-line, are not vulnerable.

The do_tmem_destroy_pool function in the Transcendent Memory (TMEM) in Xen 4.0, 4.1, and 4.2 does not properly validate pool ids, which allows local guest OS users to cause a denial of service (memory corruption and host crash) or execute arbitrary code via unspecified vectors. NOTE: this issue was originally published as part of CVE-2012-3497, which was too general; CVE-2012-3497 has been SPLIT into this ID and others.

An issue was discovered in drivers/media/platform/vivid in the Linux kernel through 5.3.8. It is exploitable for privilege escalation on some Linux distributions where local users have /dev/video0 access, but only if the driver happens to be loaded. There are multiple race conditions during streaming stopping in this driver (part of the V4L2 subsystem). These issues are caused by wrong mutex locking in vivid_stop_generating_vid_cap(), vivid_stop_generating_vid_out(), sdr_cap_stop_streaming(), and the corresponding kthreads. At least one of these race conditions leads to a use-after-free.

An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service or gain privileges by leveraging a page-writability race condition during addition of a passed-through PCI device.

An issue was discovered in Xen through 4.11.x allowing x86 guest OS users to cause a denial of service or gain privileges because grant-table transfer requests are mishandled.

The GNTTABOP_swap_grant_ref sub-operation in the grant table hypercall in Xen 4.2 and Citrix XenServer 6.0.2 allows local guest kernels or administrators to cause a denial of service (host crash) and possibly gain privileges via a crafted grant reference that triggers a write to an arbitrary hypervisor memory location.

An issue was discovered in the Linux kernel before 5.0.5. There is a use-after-free issue when hci_uart_register_dev() fails in hci_uart_set_proto() in drivers/bluetooth/hci_ldisc.c.

An out-of-bounds access issue was found in the Linux kernel, all versions through 5.3, in the way Linux kernel's KVM hypervisor implements the Coalesced MMIO write operation. It operates on an MMIO ring buffer 'struct kvm_coalesced_mmio' object, wherein write indices 'ring->first' and 'ring->last' value could be supplied by a host user-space process. An unprivileged host user or process with access to '/dev/kvm' device could use this flaw to crash the host kernel, resulting in a denial of service or potentially escalating privileges on the system.

NTFS-3G versions < 2021.8.22, a stack buffer overflow can occur when correcting differences in the MFT and MFTMirror allowing for code execution or escalation of privileges when setuid-root.

In NTFS-3G versions < 2021.8.22, when specially crafted NTFS attributes are read in the function ntfs_attr_pread_i, a heap buffer overflow can occur and allow for writing to arbitrary memory or denial of service of the application.

NTFS-3G versions < 2021.8.22, when a specially crafted NTFS attribute from the MFT is setup in the function ntfs_attr_setup_flag, a heap buffer overflow can occur allowing for code execution and escalation of privileges.

arch/powerpc/mm/mmu_context_book3s64.c in the Linux kernel before 5.1.15 for powerpc has a bug where unrelated processes may be able to read/write to one another's virtual memory under certain conditions via an mmap above 512 TB. Only a subset of powerpc systems are affected.

deepin-clone before 1.1.3 uses a predictable path /tmp/.deepin-clone/mount/<block-dev-basename> in the Helper::temporaryMountDevice() function to temporarily mount a file system as root. An unprivileged user can prepare a symlink at this location to have the file system mounted in an arbitrary location. By winning a race condition, the attacker can also enter the mount point, thereby preventing a subsequent unmount of the file system.

soffice in OpenOffice.org (OOo) 3.x before 3.3 places a zero-length directory name in the LD_LIBRARY_PATH, which allows local users to gain privileges via a Trojan horse shared library in the current working directory.

Xenstore: Guests can crash xenstored Due to a bug in the fix of XSA-115 a malicious guest can cause xenstored to use a wrong pointer during node creation in an error path, resulting in a crash of xenstored or a memory corruption in xenstored causing further damage. Entering the error path can be controlled by the guest e.g. by exceeding the quota value of maximum nodes per domain.

The Siemens R3964 line discipline driver in drivers/tty/n_r3964.c in the Linux kernel before 5.0.8 has multiple race conditions.

An issue was discovered in Xen through 4.9.x allowing PV guest OS users to cause a denial of service (host OS crash) or gain host OS privileges in shadow mode by mapping a certain auxiliary page.

In NTFS-3G versions < 2021.8.22, when a specially crafted MFT section is supplied in an NTFS image a heap buffer overflow can occur and allow for code execution.

In NTFS-3G versions < 2021.8.22, when a specially crafted unicode string is supplied in an NTFS image a heap buffer overflow can occur and allow for code execution.

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).

PoD operations on misaligned GFNs T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). The implementation of some of these hypercalls for PoD does not enforce the base page frame number to be suitably aligned for the specified order, yet some code involved in PoD handling actually makes such an assumption. These operations are XENMEM_decrease_reservation (CVE-2021-28704) and XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch 1, combining the fix to both these two issues.) In addition handling of XENMEM_decrease_reservation can also trigger a host crash when the specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).

In PHP versions 7.3.x up to and including 7.3.31, 7.4.x below 7.4.25 and 8.0.x below 8.0.12, when running PHP FPM SAPI with main FPM daemon process running as root and child worker processes running as lower-privileged users, it is possible for the child processes to access memory shared with the main process and write to it, modifying it in a way that would cause the root process to conduct invalid memory reads and writes, which can be used to escalate privileges from local unprivileged user to the root user.

certain VT-d IOMMUs may not work in shared page table mode For efficiency reasons, address translation control structures (page tables) may (and, on suitable hardware, by default will) be shared between CPUs, for second-level translation (EPT), and IOMMUs. These page tables are presently set up to always be 4 levels deep. However, an IOMMU may require the use of just 3 page table levels. In such a configuration the lop level table needs to be stripped before inserting the root table's address into the hardware pagetable base register. When sharing page tables, Xen erroneously skipped this stripping. Consequently, the guest is able to write to leaf page table entries.

Firejail before 0.9.64.4 allows attackers to bypass intended access restrictions because there is a TOCTOU race condition between a stat operation and an OverlayFS mount operation.

A race condition in Linux kernel SCTP sockets (net/sctp/socket.c) before 5.12-rc8 can lead to kernel privilege escalation from the context of a network service or an unprivileged process. If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock then an element is removed from the auto_asconf_splist list without any proper locking. This can be exploited by an attacker with network service privileges to escalate to root or from the context of an unprivileged user directly if a BPF_CGROUP_INET_SOCK_CREATE is attached which denies creation of some SCTP socket.

It was discovered freeradius up to and including version 3.0.19 does not correctly configure logrotate, allowing a local attacker who already has control of the radiusd user to escalate his privileges to root, by tricking logrotate into writing a radiusd-writable file to a directory normally inaccessible by the radiusd user. NOTE: the upstream software maintainer has stated "there is simply no way for anyone to gain privileges through this alleged issue."

Stack-based buffer overflow in the econet_sendmsg function in net/econet/af_econet.c in the Linux kernel before 2.6.36.2, when an econet address is configured, allows local users to gain privileges by providing a large number of iovec structures.