The ocaml binding for the xc_vcpu_getaffinity function in Xen 4.2.x and 4.3.x frees certain memory that may still be intended for use, which allows local users to cause a denial of service (heap corruption and crash) and possibly execute arbitrary code via unspecified vectors that trigger a (1) use-after-free or (2) double free.

IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Both AMD and Intel allow ACPI tables to specify regions of memory which should be left untranslated, which typically means these addresses should pass the translation phase unaltered. While these are typically device specific ACPI properties, they can also be specified to apply to a range of devices, or even all devices. On all systems with such regions Xen failed to prevent guests from undoing/replacing such mappings (CVE-2021-28694). On AMD systems, where a discontinuous range is specified by firmware, the supposedly-excluded middle range will also be identity-mapped (CVE-2021-28695). Further, on AMD systems, upon de-assigment of a physical device from a guest, the identity mappings would be left in place, allowing a guest continued access to ranges of memory which it shouldn't have access to anymore (CVE-2021-28696).

IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Both AMD and Intel allow ACPI tables to specify regions of memory which should be left untranslated, which typically means these addresses should pass the translation phase unaltered. While these are typically device specific ACPI properties, they can also be specified to apply to a range of devices, or even all devices. On all systems with such regions Xen failed to prevent guests from undoing/replacing such mappings (CVE-2021-28694). On AMD systems, where a discontinuous range is specified by firmware, the supposedly-excluded middle range will also be identity-mapped (CVE-2021-28695). Further, on AMD systems, upon de-assigment of a physical device from a guest, the identity mappings would be left in place, allowing a guest continued access to ranges of memory which it shouldn't have access to anymore (CVE-2021-28696).

Xen allows local OS guest users to cause a denial of service (crash) or possibly obtain sensitive information or gain privileges via vectors involving transitive grants.

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 a guest can manipulate its virtualised %cr4 in a way that is incompatible with Linux (and possibly other guest kernels).

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 incorrect use of the HVM physmap concept for PV domains.

The x86 emulator in Xen does not properly treat x86 NULL segments as unusable when accessing memory, which might allow local HVM guest users to gain privileges via vectors involving "unexpected" base/limit values.

Xen 4.0.x through 4.7.x mishandle x86 task switches to VM86 mode, which allows local 32-bit x86 HVM guest OS users to gain privileges or cause a denial of service (guest OS crash) by leveraging a guest operating system that uses hardware task switching and allows a new task to start in VM86 mode.

An issue was discovered in Xen through 4.14.x. Access rights of Xenstore nodes are per domid. Unfortunately, existing granted access rights are not removed when a domain is being destroyed. This means that a new domain created with the same domid will inherit the access rights to Xenstore nodes from the previous domain(s) with the same domid. Because all Xenstore entries of a guest below /local/domain/<domid> are being deleted by Xen tools when a guest is destroyed, only Xenstore entries of other guests still running are affected. For example, a newly created guest domain might be able to read sensitive information that had belonged to a previously existing guest domain. Both Xenstore implementations (C and Ocaml) are vulnerable.

network backend may cause Linux netfront to use freed SKBs While adding logic to support XDP (eXpress Data Path), a code label was moved in a way allowing for SKBs having references (pointers) retained for further processing to nevertheless be freed.

An issue was discovered in Xen through 4.14.x allowing x86 PV guest OS users to gain guest OS privileges by modifying kernel memory contents, because invalidation of TLB entries is mishandled during use of an INVLPG-like attack technique.

An issue was discovered in Xen through 4.14.x allowing x86 HVM guest OS users to cause a denial of service (stack corruption), cause a data leak, or possibly gain privileges because of an off-by-one error. NOTE: this issue is caused by an incorrect fix for CVE-2020-27671.

Heap-based buffer overflow in the pcnet_receive function in hw/net/pcnet.c in QEMU allows guest OS administrators to cause a denial of service (instance crash) or possibly execute arbitrary code via a series of packets in loopback mode.

Xen 4.4.x, when running on an ARM system and "handling an unknown system register access from 64-bit userspace," returns to an instruction of the trap handler for kernel space faults instead of an instruction that is associated with faults in 64-bit userspace, which allows local guest users to cause a denial of service (crash) and possibly gain privileges via a crafted process.

Use-after-free vulnerability in the xc_cpupool_getinfo function in Xen 4.1.x through 4.3.x, when using a multithreaded toolstack, does not properly handle a failure by the xc_cpumap_alloc function, which allows local users with access to management functions to cause a denial of service (heap corruption) and possibly gain privileges via unspecified vectors.

arm: guest_physmap_remove_page not removing the p2m mappings The functions to remove one or more entries from a guest p2m pagetable on Arm (p2m_remove_mapping, guest_physmap_remove_page, and p2m_set_entry with mfn set to INVALID_MFN) do not actually clear the pagetable entry if the entry doesn't have the valid bit set. It is possible to have a valid pagetable entry without the valid bit set when a guest operating system uses set/way cache maintenance instructions. For instance, a guest issuing a set/way cache maintenance instruction, then calling the XENMEM_decrease_reservation hypercall to give back memory pages to Xen, might be able to retain access to those pages even after Xen started reusing them for other purposes.

An issue was discovered in the Linux kernel 5.5 through 5.7.9, as used in Xen through 4.13.x for x86 PV guests. An attacker may be granted the I/O port permissions of an unrelated task. This occurs because tss_invalidate_io_bitmap mishandling causes a loss of synchronization between the I/O bitmaps of TSS and Xen, aka CID-cadfad870154.

An issue was discovered in Xen through 4.9.x allowing x86 SVM PV guest OS users to cause a denial of service (hypervisor crash) or gain privileges because IDT settings are mishandled during CPU hotplugging.

An issue was discovered in Xen through 4.9.x allowing x86 guest OS users to cause a denial of service (hypervisor crash) or possibly gain privileges because MSI mapping was mishandled.

An issue was discovered in Xen through 4.14.x. There are missing memory barriers when accessing/allocating an event channel. Event channels control structures can be accessed lockless as long as the port is considered to be valid. Such a sequence is missing an appropriate memory barrier (e.g., smp_*mb()) to prevent both the compiler and CPU from re-ordering access. A malicious guest may be able to cause a hypervisor crash resulting in a Denial of Service (DoS). Information leak and privilege escalation cannot be excluded. Systems running all versions of Xen are affected. Whether a system is vulnerable will depend on the CPU and compiler used to build Xen. For all systems, the presence and the scope of the vulnerability depend on the precise re-ordering performed by the compiler used to build Xen. We have not been able to survey compilers; consequently we cannot say which compiler(s) might produce vulnerable code (with which code generation options). GCC documentation clearly suggests that re-ordering is possible. Arm systems will also be vulnerable if the CPU is able to re-order memory access. Please consult your CPU vendor. x86 systems are only vulnerable if a compiler performs re-ordering.

grant table v2 status pages may remain accessible after de-allocation Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes.

PCI devices with RMRRs not deassigned correctly Certain PCI devices in a system might be assigned Reserved Memory Regions (specified via Reserved Memory Region Reporting, "RMRR"). These are typically used for platform tasks such as legacy USB emulation. If such a device is passed through to a guest, then on guest shutdown the device is not properly deassigned. The IOMMU configuration for these devices which are not properly deassigned ends up pointing to a freed data structure, including the IO Pagetables. Subsequent DMA or interrupts from the device will have unpredictable behaviour, ranging from IOMMU faults to memory corruption.

IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Both AMD and Intel allow ACPI tables to specify regions of memory which should be left untranslated, which typically means these addresses should pass the translation phase unaltered. While these are typically device specific ACPI properties, they can also be specified to apply to a range of devices, or even all devices. On all systems with such regions Xen failed to prevent guests from undoing/replacing such mappings (CVE-2021-28694). On AMD systems, where a discontinuous range is specified by firmware, the supposedly-excluded middle range will also be identity-mapped (CVE-2021-28695). Further, on AMD systems, upon de-assigment of a physical device from a guest, the identity mappings would be left in place, allowing a guest continued access to ranges of memory which it shouldn't have access to anymore (CVE-2021-28696).

The pygrub boot loader emulator in Xen, when nul-delimited output format is requested, allows local pygrub-using guest OS administrators to read or delete arbitrary files on the host via NUL bytes in the bootloader configuration file.

The pygrub boot loader emulator in Xen, when S-expression output format is requested, allows local pygrub-using guest OS administrators to read or delete arbitrary files on the host via string quotes and S-expressions in the bootloader configuration file.

Xen through 4.8.x allows local 64-bit x86 HVM guest OS users to gain privileges by leveraging mishandling of SYSCALL singlestep during emulation.

The pyGrub boot loader in Xen 3.0.3, 3.3.0, and Xen-3.3.1 does not support the password option in grub.conf for para-virtualized guests, which allows attackers with access to the para-virtualized guest console to boot the guest or modify the guest's kernel boot parameters without providing the expected password.

The VNC server implementation in QEMU, as used by Xen and possibly other environments, allows local users of a guest operating system to read arbitrary files on the host operating system via unspecified vectors related to QEMU monitor mode, as demonstrated by mapping files to a CDROM device. NOTE: some of these details are obtained from third party information.

Barron McCann X-Kryptor Driver BMS1446HRR (Xgntr BMS1351 Install BMS1472) in X-Kryptor Secure Client does not drop privileges when launching an Explorer window in response to a help command, which allows local users to gain LocalSystem privileges via interactive use of Explorer.

The ReadDirectoryChangesW API function on Microsoft Windows 2000, XP, Server 2003, and Vista does not check permissions for child objects, which allows local users to bypass permissions by opening a directory with LIST (READ) access and using ReadDirectoryChangesW to monitor changes of files that do not have LIST permissions, which can be leveraged to determine filenames, access times, and other sensitive information.

In cPanel before 67.9999.103, the backup system overwrites root's home directory when a mount disappears (SEC-299).

In Arista's MOS (Metamako Operating System) software which is supported on the 7130 product line, under certain conditions, the bash shell might be accessible to unprivileged users in situations where they should not have access. This issue affects: Arista Metamako Operating System All releases in the MOS-0.1x train MOS-0.26.6 and below releases in the MOS-0.2x train MOS-0.31.1 and below releases in the MOS-0.3x train

The NtUserConsoleControl function in win32k.sys in Microsoft Windows XP SP2 and SP3, and Server 2003 before SP1, allows local administrators to bypass unspecified "security software" and gain privileges via a crafted call that triggers an overwrite of an arbitrary memory location. NOTE: the vendor disputes the significance of this report, stating that 'the Administrator to SYSTEM "escalation" is not a security boundary we defend.

nilfs-utils before 2.0.14 installs multiple programs with unnecessary setuid privileges, which allows local users to execute arbitrary commands via the device string in a -c command line option to mkfs.nilfs2.

Privilege Escalation vulnerability in McAfee FRP 5.x prior to 5.1.0.209 allows local users to gain elevated privileges via running McAfee Tray with elevated privileges.

hald in Sun OpenSolaris snv_51 through snv_130 does not have the proc_audit privilege during unspecified attempts to write to the auditing log, which makes it easier for physically proximate attackers to avoid detection of changes to the set of connected hardware devices supporting the Hardware Abstraction Layer (HAL) specification.

The Shibboleth authentication module 5.x before 5.x-3.4 and 6.x before 6.x-3.2, a module for Drupal, does not properly remove statically granted privileges after a logout or other session change, which allows physically proximate attackers to gain privileges by using an unattended web browser.

The Self Tuning Memory Manager (STMM) component in IBM DB2 9.1 before FP8, 9.5 before FP5, and 9.7 before FP1 uses 0666 permissions for the STMM log file, which allows local users to cause a denial of service or have unspecified other impact by writing to this file.

A vulnerability in the routine that loads DLL files in Cisco Meeting App for Windows could allow an authenticated, local attacker to run an executable file with privileges equivalent to those of Cisco Meeting App. The vulnerability is due to incomplete input validation of the path name for DLL files before they are loaded. An attacker could exploit this vulnerability by installing a crafted DLL file in a specific system directory. A successful exploit could allow the attacker to execute commands on the underlying Microsoft Windows host with privileges equivalent to those of Cisco Meeting App. The attacker would need valid user credentials to exploit this vulnerability. Cisco Bug IDs: CSCvd77907.

A vulnerability in the guest shell feature of Cisco NX-OS System Software could allow an authenticated, local attacker to read and send packets outside the scope of the guest shell container. An attacker would need valid administrator credentials to perform this attack. The vulnerability is due to insufficient internal security measures in the guest shell feature. An attacker could exploit this vulnerability by sending or receiving packets on the device-internal network outside of the guest shell container, aka "Unauthorized Internal Interface Access." This vulnerability affects the following products running Cisco NX-OS System Software: Nexus 3000 Series Switches, Nexus 9000 Series Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules. Cisco Bug IDs: CSCvf33038.

dasauto in IBM DB2 8 before FP18, 9.1 before FP8, 9.5 before FP4, and 9.7 before FP1 permits execution by unprivileged user accounts, which has unspecified impact and local attack vectors.

A vulnerability in the Open Agent Container (OAC) feature of Cisco Nexus Series Switches could allow an unauthenticated, local attacker to read and send packets outside the scope of the OAC. The vulnerability is due to insufficient internal security measures in the OAC feature. An attacker could exploit this vulnerability by crafting specific packets for communication on the device-internal network. A successful exploit could allow the attacker to run code on the underlying host operating system. OAC is not enabled by default. For a device to be vulnerable, an administrator would need to install and activate this feature. This vulnerability affects the following Cisco Nexus Series Switches: Nexus 2000 Series Fabric Extenders, Nexus 5000 Series Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches. Cisco Bug IDs: CSCve53542, CSCvf36621.

incron 0.5.5 does not initialize supplementary groups when running a process from a user's incrontabs, which causes the process to be run with the incrond supplementary groups and allows local users to gain privileges via an incrontab table.

The RBAC functionality in grsecurity before 2.1.11-2.6.24.5 and 2.1.11-2.4.36.2 does not enforce user_transition_deny and user_transition_allow rules for the (1) sys_setfsuid and (2) sys_setfsgid calls, which allows local users to bypass restrictions for those calls.

NFSv4 in the Linux kernel 2.6.18, and possibly other versions, does not properly clean up an inode when an O_EXCL create fails, which causes files to be created with insecure settings such as setuid bits, and possibly allows local users to gain privileges, related to the execution of the do_open_permission function even when a create fails.

The kernel in NetBSD, probably 5.0.1 and earlier, on x86 platforms does not properly handle a pre-commit failure of the iret instruction, which might allow local users to gain privileges via vectors related to a tempEIP pseudocode variable that is outside of the code-segment limits.

The (1) Simplified Chinese, (2) Traditional Chinese, (3) Korean, and (4) Thai language input methods in Sun Solaris 10 create files and directories with weak permissions under (a) .iiim/le and (b) .Xlocale in home directories, which might allow local users to write to, or read from, the home directories of other users.

IBM DB2 8.1 before FP18 allows attackers to obtain unspecified access via a das command.

Multiple unspecified vulnerabilities in IBM Hardware Management Console (HMC) 7 R3.2.0 allow attackers to gain privileges via "some HMC commands."

A vulnerability in the AntivirusforMac binary as used in Bitdefender Antivirus for Mac allows an attacker to inject a library using DYLD environment variable to cause third-party code execution