pam_motd (aka the MOTD module) in libpam-modules before 1.1.0-2ubuntu1.1 in PAM on Ubuntu 9.10 and libpam-modules before 1.1.1-2ubuntu5 in PAM on Ubuntu 10.04 LTS allows local users to change the ownership of arbitrary files via a symlink attack on .cache in a user's home directory, related to "user file stamps" and the motd.legal-notice file.

The postfix.postinst script in the Debian GNU/Linux and Ubuntu postfix 2.5.5 package grants the postfix user write access to /var/spool/postfix/pid, which might allow local users to conduct symlink attacks that overwrite arbitrary files.

trend-autoupdate.new in mailscanner 4.55.10 and other versions before 4.74.16-1 allows local users to overwrite arbitrary files via a symlink attack on a (1) /tmp/opr.ini.##### or (2) /tmp/lpt*.zip temporary file.

gccross in dpkg-cross 2.3.0 allows local users to overwrite arbitrary files via a symlink attack on the tmp/gccross2.log temporary file. NOTE: the vendor disputes this vulnerability, stating that "There is no sense in this bug - the script ... is called under specific cross-building environments within a chroot.

init in initramfs-tools 0.92f allows local users to overwrite arbitrary files via a symlink attack on the /tmp/initramfs.debug temporary file. NOTE: the vendor disputes this vulnerability, stating that "init is [used in] a single-user context; there's no possibility that this is exploitable.

migrate_aliases.sh in Citadel Server 7.37 allows local users to overwrite arbitrary files via a symlink attack on a temporary file.

test.sh in Honeyd 1.5c might allow local users to overwrite arbitrary files via a symlink attack on a temporary file.

ltpmenu in ltp 20060918 allows local users to overwrite arbitrary files via a symlink attack on a /tmp/runltp.mainmenu.##### temporary file.

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.

snapd 2.54.2 did not properly validate the location of the snap-confine binary. A local attacker who can hardlink this binary to another location to cause snap-confine to execute other arbitrary binaries and hence gain privilege escalation. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1

The init script in the Debian x11-common package before 1:7.6+12 is vulnerable to a symlink attack that can lead to a privilege escalation during package installation.

i2myspell in myspell 3.1 allows local users to overwrite arbitrary files via a symlink attack on (1) /tmp/i2my#####.1 and (2) /tmp/i2my#####.2 temporary files.

mkmailpost in newsgate 1.6 allows local users to overwrite arbitrary files via a symlink attack on a /tmp/mmp##### temporary file.

The (1) mdb and (2) mdb-symbolreader scripts in mono-debugger 2.4.3, and other versions before 2.8.1, place 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.

In multiple functions of io_uring.c, there is a possible kernel memory corruption due to improper locking. This could lead to local escalation of privilege in the kernel with System execution privileges needed. User interaction is not needed for exploitation.

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.

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.

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.

Exim 4.72 and earlier allows local users to gain privileges by leveraging the ability of the exim user account to specify an alternate configuration file with a directive that contains arbitrary commands, as demonstrated by the spool_directory directive.

Multiple race conditions in fs/pipe.c in the Linux kernel before 2.6.32-rc6 allow local users to cause a denial of service (NULL pointer dereference and system crash) or gain privileges by attempting to open an anonymous pipe via a /proc/*/fd/ pathname.

In the Linux Kernel before version 4.16.11, 4.14.43, 4.9.102, and 4.4.133, multiple race condition errors when handling probe, disconnect, and rebind operations can be exploited to trigger a use-after-free condition or a NULL pointer dereference by sending multiple USB over IP packets.

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.

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.

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.

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.

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.

An issue was discovered in Xen through 4.11.x on AMD x86 platforms, possibly allowing guest OS users to gain host OS privileges because TLB flushes do not always occur after IOMMU mapping changes.

An issue was discovered in Xen through 4.11.x on AMD x86 platforms, possibly allowing guest OS users to gain host OS privileges because small IOMMU mappings are unsafely combined into larger ones.

The prepend_path function in fs/dcache.c in the Linux kernel before 4.2.4 does not properly handle rename actions inside a bind mount, which allows local users to bypass an intended container protection mechanism by renaming a directory, related to a "double-chroot attack."

In NTFS-3G versions < 2021.8.22, when a specially crafted NTFS attribute is supplied to the function ntfs_get_attribute_value, a heap buffer overflow can occur allowing for memory disclosure or denial of service. The vulnerability is caused by an out-of-bound buffer access which can be triggered by mounting a crafted ntfs partition. The root cause is a missing consistency check after reading an MFT record : the "bytes_in_use" field should be less than the "bytes_allocated" field. When it is not, the parsing of the records proceeds into the wild.

A flaw was found in the Linux kernel's handle_rx() function in the [vhost_net] driver. A malicious virtual guest, under specific conditions, can trigger an out-of-bounds write in a kmalloc-8 slab on a virtual host which may lead to a kernel memory corruption and a system panic. Due to the nature of the flaw, privilege escalation cannot be fully ruled out. Versions from v4.16 and newer are vulnerable.

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.

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.

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.

A race condition in chown_one() of systemd allows an attacker to cause systemd to set arbitrary permissions on arbitrary files. Affected releases are systemd versions up to and including 239.

When sending malicous data to kernel by ioctl cmd FBIOPUT_VSCREENINFO,kernel will write memory out of bounds.

An insecure default to allow UEFI Shell in EDK2 was left enabled in LXD. This allows an OS-resident attacker to bypass Secure Boot.

An insecure default to allow UEFI Shell in EDK2 was left enabled in Ubuntu's EDK2. This allows an OS-resident attacker to bypass Secure Boot.

Race condition in the key_gc_unused_keys function in security/keys/gc.c in the Linux kernel through 3.18.2 allows local users to cause a denial of service (memory corruption or panic) or possibly have unspecified other impact via keyctl commands that trigger access to a key structure member during garbage collection of a key.

issues with partially successful P2M updates on x86 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). In some cases the hypervisor carries out the requests by splitting them into smaller chunks. Error handling in certain PoD cases has been insufficient in that in particular partial success of some operations was not properly accounted for. There are two code paths affected - page removal (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix to both issues.)

issues with partially successful P2M updates on x86 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). In some cases the hypervisor carries out the requests by splitting them into smaller chunks. Error handling in certain PoD cases has been insufficient in that in particular partial success of some operations was not properly accounted for. There are two code paths affected - page removal (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix to both issues.)

Protection mechanism failure for some Intel(R) PROSet/Wireless WiFi software may allow a privileged user to potentially enable escalation of privilege via local access.

A flaw was found in the exFAT driver of the Linux kernel. The vulnerability exists in the implementation of the file name reconstruction function, which is responsible for reading file name entries from a directory index and merging file name parts belonging to one file into a single long file name. Since the file name characters are copied into a stack variable, a local privileged attacker could use this flaw to overflow the kernel stack.

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).

hw/pci/msix.c in QEMU 4.2.0 allows guest OS users to trigger an out-of-bounds access via a crafted address in an msi-x mmio operation.

An issue was discovered in the Linux kernel through 5.6.11. sg_write lacks an sg_remove_request call in a certain failure case, aka CID-83c6f2390040.

In Apache SpamAssassin before 3.4.3, nefarious CF files can be configured to run system commands without any output or errors. With this, exploits can be injected in a number of scenarios. In addition to upgrading to SA 3.4.3, we recommend that users should only use update channels or 3rd party .cf files from trusted places.

The InfiniBand (IB) implementation in the Linux kernel package before 2.6.32-504.12.2 on Red Hat Enterprise Linux (RHEL) 6 does not properly restrict use of User Verbs for registration of memory regions, which allows local users to access arbitrary physical memory locations, and consequently cause a denial of service (system crash) or gain privileges, by leveraging permissions on a uverbs device under /dev/infiniband/.

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.