An issue was discovered in Xen through 4.14.x. In the Ocaml xenstored implementation, the internal representation of the tree has special cases for the root node, because this node has no parent. Unfortunately, permissions were not checked for certain operations on the root node. Unprivileged guests can get and modify permissions, list, and delete the root node. (Deleting the whole xenstore tree is a host-wide denial of service.) Achieving xenstore write access is also possible. 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.

xrdp is an open source remote desktop protocol (RDP) server. In affected versions an integer underflow leading to a heap overflow in the sesman server allows any unauthenticated attacker which is able to locally access a sesman server to execute code as root. This vulnerability has been patched in version 0.9.18.1 and above. Users are advised to upgrade. There are no known workarounds.

An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped. However, the handler may not have time to run if the frontend quickly toggles between the states connect and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. Privilege escalation and information leaks cannot be ruled out. This only affects systems with a Linux blkback.

A flaw was found in xorg-x11-server in versions before 21.1.2 and before 1.20.14. An out-of-bounds access can occur in the SwapCreateRegister function. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in xorg-x11-server in versions before 21.1.2 and before 1.20.14. An out-of-bounds access can occur in the SProcScreenSaverSuspend function. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A flaw was found in xorg-x11-server in versions before 21.1.2 and before 1.20.14. An out-of-bounds access can occur in the SProcXFixesCreatePointerBarrier function. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A use after free in the Linux kernel File System notify functionality was found in the way user triggers copy_info_records_to_user() call to fail in copy_event_to_user(). A local user could use this flaw to crash the system or potentially escalate their privileges on the system.

In cifs-utils through 6.14, a stack-based buffer overflow when parsing the mount.cifs ip= command-line argument could lead to local attackers gaining root privileges.

An out-of-bounds (OOB) memory write flaw was found in the Linux kernel’s watch_queue event notification subsystem. This flaw can overwrite parts of the kernel state, potentially allowing a local user to gain privileged access or cause a denial of service on the system.

Sympa through 6.2.57b.2 allows a local privilege escalation from the sympa user account to full root access by modifying the sympa.conf configuration file (which is owned by sympa) and parsing it through the setuid sympa_newaliases-wrapper executable.

A flaw was found in grub2 in versions prior to 2.06. During USB device initialization, descriptors are read with very little bounds checking and assumes the USB device is providing sane values. If properly exploited, an attacker could trigger memory corruption leading to arbitrary code execution allowing a bypass of the Secure Boot mechanism. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

x86 pv: Insufficient care with non-coherent mappings T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Xen maintains a type reference count for pages, in addition to a regular reference count. This scheme is used to maintain invariants required for Xen's safety, e.g. PV guests may not have direct writeable access to pagetables; updates need auditing by Xen. Unfortunately, Xen's safety logic doesn't account for CPU-induced cache non-coherency; cases where the CPU can cause the content of the cache to be different to the content in main memory. In such cases, Xen's safety logic can incorrectly conclude that the contents of a page is safe.

x86 pv: Insufficient care with non-coherent mappings T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Xen maintains a type reference count for pages, in addition to a regular reference count. This scheme is used to maintain invariants required for Xen's safety, e.g. PV guests may not have direct writeable access to pagetables; updates need auditing by Xen. Unfortunately, Xen's safety logic doesn't account for CPU-induced cache non-coherency; cases where the CPU can cause the content of the cache to be different to the content in main memory. In such cases, Xen's safety logic can incorrectly conclude that the contents of a page is safe.

AIDE before 0.17.4 allows local users to obtain root privileges via crafted file metadata (such as XFS extended attributes or tmpfs ACLs), because of a heap-based buffer overflow.

A vulnerability was found in Linux Kernel where refcount leak in llcp_sock_bind() causing use-after-free which might lead to privilege escalations.

The DBLink module in PostgreSQL 8.2 before 8.2.6, 8.1 before 8.1.11, 8.0 before 8.0.15, 7.4 before 7.4.19, and 7.3 before 7.3.21, when local trust or ident authentication is used, allows remote attackers to gain privileges via unspecified vectors. NOTE: this issue exists because of an incomplete fix for CVE-2007-3278.

An issue was discovered in TrouSerS through 0.3.14. If the tcsd daemon is started with root privileges instead of by the tss user, it fails to drop the root gid privilege when no longer needed.

An issue was discovered in TrouSerS through 0.3.14. If the tcsd daemon is started with root privileges, the tss user still has read and write access to the /etc/tcsd.conf file (which contains various settings related to this daemon).

A flaw was found in the KVM's AMD code for supporting the Secure Encrypted Virtualization-Encrypted State (SEV-ES). A KVM guest using SEV-ES can trigger out-of-bounds reads and writes in the host kernel via a malicious VMGEXIT for a string I/O instruction (for example, outs or ins) using the exit reason SVM_EXIT_IOIO. This issue results in a crash of the entire system or a potential guest-to-host escape scenario.

In HylaFAX+ through 7.0.2 and HylaFAX Enterprise, the faxsetup utility calls chown on files in user-owned directories. By winning a race, a local attacker could use this to escalate his privileges to root.

Sympa before 6.2.56 allows privilege escalation.

In finalize of AssetManager.java, there is possible memory corruption due to a double free. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-8.0 Android-8.1 Android-9 Android-10Android ID: A-144028297

A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe and push_pipe functions in the Linux kernel and could thus contain stale values. An unprivileged local user could use this flaw to write to pages in the page cache backed by read only files and as such escalate their privileges on the system.

A flaw was found in unrestricted eBPF usage by the BPF_BTF_LOAD, leading to a possible out-of-bounds memory write in the Linux kernel’s BPF subsystem due to the way a user loads BTF. This flaw allows a local user to crash or escalate their privileges on the system.

In Zsh before 5.8, attackers able to execute commands can regain privileges dropped by the --no-PRIVILEGED option. Zsh fails to overwrite the saved uid, so the original privileges can be restored by executing MODULE_PATH=/dir/with/module zmodload with a module that calls setuid().

An issue was discovered in Xen through 4.12.x allowing attackers to gain host OS privileges via DMA in a situation where an untrusted domain has access to a physical device (and assignable-add is not used), because of an incomplete fix for CVE-2019-18424. XSA-302 relies on the use of libxl's "assignable-add" feature to prepare devices to be assigned to untrusted guests. Unfortunately, this is not considered a strictly required step for device assignment. The PCI passthrough documentation on the wiki describes alternate ways of preparing devices for assignment, and libvirt uses its own ways as well. Hosts where these "alternate" methods are used will still leave the system in a vulnerable state after the device comes back from a guest. An untrusted domain with access to a physical device can DMA into host memory, leading to privilege escalation. Only systems where guests are given direct access to physical devices capable of DMA (PCI pass-through) are vulnerable. Systems which do not use PCI pass-through are not vulnerable.

The x86-64 kernel system-call functionality in Xen 4.1.2 and earlier, as used in Citrix XenServer 6.0.2 and earlier and other products; Oracle Solaris 11 and earlier; illumos before r13724; Joyent SmartOS before 20120614T184600Z; FreeBSD before 9.0-RELEASE-p3; NetBSD 6.0 Beta and earlier; Microsoft Windows Server 2008 R2 and R2 SP1 and Windows 7 Gold and SP1; and possibly other operating systems, when running on an Intel processor, incorrectly uses the sysret path in cases where a certain address is not a canonical address, which allows local users to gain privileges via a crafted application. NOTE: because this issue is due to incorrect use of the Intel specification, it should have been split into separate identifiers; however, there was some value in preserving the original mapping of the multi-codebase coordinated-disclosure effort to a single identifier.

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.

loop_rw_iter in fs/io_uring.c in the Linux kernel 5.10 through 5.14.6 allows local users to gain privileges by using IORING_OP_PROVIDE_BUFFERS to trigger a free of a kernel buffer, as demonstrated by using /proc/<pid>/maps for exploitation.

An issue was discovered in Xen through 4.9.x allowing HVM guest OS users to gain privileges on the host OS, obtain sensitive information, or cause a denial of service (BUG and host OS crash) by leveraging the mishandling of Populate on Demand (PoD) Physical-to-Machine (P2M) errors.

containerd is an open source container runtime with an emphasis on simplicity, robustness and portability. A bug was found in containerd where container root directories and some plugins had insufficiently restricted permissions, allowing otherwise unprivileged Linux users to traverse directory contents and execute programs. When containers included executable programs with extended permission bits (such as setuid), unprivileged Linux users could discover and execute those programs. When the UID of an unprivileged Linux user on the host collided with the file owner or group inside a container, the unprivileged Linux user on the host could discover, read, and modify those files. This vulnerability has been fixed in containerd 1.4.11 and containerd 1.5.7. Users should update to these version when they are released and may restart containers or update directory permissions to mitigate the vulnerability. Users unable to update should limit access to the host to trusted users. Update directory permission on container bundles directories.

An issue was discovered in Xen through 4.9.x allowing x86 HVM guest OS users to cause a denial of service (hypervisor crash) or possibly gain privileges because self-linear shadow mappings are mishandled for translated guests.

A flaw was found in xorg-x11-server in versions before 21.1.2 and before 1.20.14. An out-of-bounds access can occur in the SProcRenderCompositeGlyphs function. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A parameter verification issue was discovered in Xen through 4.9.x. The function `alloc_heap_pages` allows callers to specify the first NUMA node that should be used for allocations through the `memflags` parameter; the node is extracted using the `MEMF_get_node` macro. While the function checks to see if the special constant `NUMA_NO_NODE` is specified, it otherwise does not handle the case where `node >= MAX_NUMNODES`. This allows an out-of-bounds access to an internal array.

The xen_biovec_phys_mergeable function in drivers/xen/biomerge.c in Xen might allow local OS guest users to corrupt block device data streams and consequently obtain sensitive memory information, cause a denial of service, or gain host OS privileges by leveraging incorrect block IO merge-ability calculation.

An out-of-bounds memory write flaw was found in the Linux kernel's joystick devices subsystem in versions before 5.9-rc1, in the way the user calls ioctl JSIOCSBTNMAP. This flaw allows a local user to crash the system or possibly escalate their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

A grant unmapping issue was discovered in Xen through 4.9.x. When removing or replacing a grant mapping, the x86 PV specific path needs to make sure page table entries remain in sync with other accounting done. Although the identity of the page frame was validated correctly, neither the presence of the mapping nor page writability were taken into account.

Xen, when running on a 64-bit hypervisor, allows local x86 guest OS users to modify arbitrary memory and consequently obtain sensitive information, cause a denial of service (host crash), or execute arbitrary code on the host by leveraging broken emulation of bit test instructions.

An issue was discovered in the Linux kernel through 5.10.11. PI futexes have a kernel stack use-after-free during fault handling, allowing local users to execute code in the kernel, aka CID-34b1a1ce1458.

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.

Sudo before 1.9.5p2 contains an off-by-one error that can result in a heap-based buffer overflow, which allows privilege escalation to root via "sudoedit -s" and a command-line argument that ends with a single backslash character.

The PV pagetable code in arch/x86/mm.c in Xen 4.7.x and earlier allows local 32-bit PV guest OS administrators to gain host OS privileges by leveraging fast-paths for updating pagetable entries.

SELinux policycoreutils allows local users to execute arbitrary commands outside of the sandbox via a crafted TIOCSTI ioctl call.

There is heap-based buffer overflow in kernel, all versions up to, excluding 5.3, in the marvell wifi chip driver in Linux kernel, that allows local users to cause a denial of service(system crash) or possibly execute arbitrary code.

Bash before 4.4 allows local users to execute arbitrary commands with root privileges via crafted SHELLOPTS and PS4 environment variables.

Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect handling of a copy-on-write (COW) feature to write to a read-only memory mapping, as exploited in the wild in October 2016, aka "Dirty COW."

Xen 4.5.3, 4.6.3, and 4.7.x allow local HVM guest OS administrators to overwrite hypervisor memory and consequently gain host OS privileges by leveraging mishandling of instruction pointer truncation during emulation.