In the Linux kernel 4.19 through 5.6.7 on the s390 platform, code execution may occur because of a race condition, as demonstrated by code in enable_sacf_uaccess in arch/s390/lib/uaccess.c that fails to protect against a concurrent page table upgrade, aka CID-3f777e19d171. A crash could also occur.
Race condition in the directory notification subsystem (dnotify) in Linux kernel 2.6.x before 2.6.24.6, and 2.6.25 before 2.6.25.1, allows local users to cause a denial of service (OOPS) and possibly gain privileges via unspecified vectors.
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.
KDE kdelibs before 4.14 and kauth before 5.1 does not properly use D-Bus for communication with a polkit authority, which allows local users to bypass intended access restrictions by leveraging a PolkitUnixProcess PolkitSubject race condition via a (1) setuid process or (2) pkexec process, related to CVE-2013-4288 and "PID reuse race conditions."
The n_tty_write function in drivers/tty/n_tty.c in the Linux kernel through 3.14.3 does not properly manage tty driver access in the "LECHO & !OPOST" case, which allows local users to cause a denial of service (memory corruption and system crash) or gain privileges by triggering a race condition involving read and write operations with long strings.
In the Linux kernel before 5.17.3, fs/io_uring.c has a use-after-free due to a race condition in io_uring timeouts. This can be triggered by a local user who has no access to any user namespace; however, the race condition perhaps can only be exploited infrequently.
systemd does not properly use D-Bus for communication with a polkit authority, which allows local users to bypass intended access restrictions by leveraging a PolkitUnixProcess PolkitSubject race condition via a (1) setuid process or (2) pkexec process, a related issue to CVE-2013-4288.
A race condition flaw was found in the 9pfs server implementation of QEMU up to and including 5.2.0. This flaw allows a malicious 9p client to cause a use-after-free error, potentially escalating their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity as well as system availability.
An issue was discovered in Xen through 4.14.x allowing x86 guest OS users to cause a host OS denial of service, achieve data corruption, or possibly gain privileges by exploiting a race condition that leads to a use-after-free involving 2MiB and 1GiB superpages.
x86 pv: Race condition in typeref acquisition 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, the logic for acquiring a type reference has a race condition, whereby a safely TLB flush is issued too early and creates a window where the guest can re-establish the read/write mapping before writeability is prohibited.
A flaw was found in Linux Kernel because access to the global variable fg_console is not properly synchronized leading to a use after free in con_font_op.
A use-after-free flaw was found in the Linux kernel’s sound subsystem in the way a user triggers concurrent calls of PCM hw_params. The hw_free ioctls or similar race condition happens inside ALSA PCM for other ioctls. This flaw allows a local user to crash or potentially escalate their privileges on the system.
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.
A race condition existed in the snapd 2.54.2 snap-confine binary when preparing a private mount namespace for a snap. This could allow a local attacker to gain root privileges by bind-mounting their own contents inside the snap's private mount namespace and causing snap-confine to execute arbitrary code 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
A read-after-free memory flaw was found in the Linux kernel's garbage collection for Unix domain socket file handlers in the way users call close() and fget() simultaneously and can potentially trigger a race condition. This flaw allows a local user to crash the system or escalate their privileges on the system. This flaw affects Linux kernel versions prior to 5.16-rc4.
The Linux kernel before 3.15.4 on Intel processors does not properly restrict use of a non-canonical value for the saved RIP address in the case of a system call that does not use IRET, which allows local users to leverage a race condition and gain privileges, or cause a denial of service (double fault), via a crafted application that makes ptrace and fork system calls.
Race condition in drivers/tty/n_hdlc.c in the Linux kernel through 4.10.1 allows local users to gain privileges or cause a denial of service (double free) by setting the HDLC line discipline.
An issue was discovered in Xen through 4.9.x allowing x86 PV guest OS users to execute arbitrary code on the host OS because of a race condition that can cause a stale TLB entry.
Product: AndroidVersions: Android kernelAndroid ID: A-173788806References: Upstream kernel
Race condition in QEMU in Xen allows local x86 HVM guest OS administrators to gain privileges by changing certain data on shared rings, aka a "double fetch" vulnerability.
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.
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.
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.
The Siemens R3964 line discipline driver in drivers/tty/n_r3964.c in the Linux kernel before 5.0.8 has multiple race conditions.
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.
In unix_scm_to_skb of af_unix.c, there is a possible use after free bug due to a race condition. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-196926917References: Upstream kernel
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.
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.
ltpmenu in ltp 20060918 allows local users to overwrite arbitrary files via a symlink attack on a /tmp/runltp.mainmenu.##### 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.
qemu-dm.debug in Xen 3.2.1 allows local users to overwrite arbitrary files via a symlink attack on the /tmp/args temporary file.
mkmailpost in newsgate 1.6 allows local users to overwrite arbitrary files via a symlink attack on a /tmp/mmp##### temporary file.
test.sh in Honeyd 1.5c might allow local users to overwrite arbitrary files via a symlink attack on a temporary file.
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 4.11 allowing HVM guest OS users to cause a denial of service (host OS crash) or possibly gain host OS privileges because x86 IOREQ server resource accounting (for external emulators) was mishandled.
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.
migrate_aliases.sh in Citadel Server 7.37 allows local users to overwrite arbitrary files via a symlink attack on a temporary file.
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.
PostgreSQL 8.1 and probably later versions, when local trust authentication is enabled and the Database Link library (dblink) is installed, allows remote attackers to access arbitrary accounts and execute arbitrary SQL queries via a dblink host parameter that proxies the connection from 127.0.0.1.
The pit_ioport_read in i8254.c in the Linux kernel before 2.6.33 and QEMU before 2.3.1 does not distinguish between read lengths and write lengths, which might allow guest OS users to execute arbitrary code on the host OS by triggering use of an invalid index.
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."
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/.
The PPPoL2TP feature in net/l2tp/l2tp_ppp.c in the Linux kernel through 3.15.6 allows local users to gain privileges by leveraging data-structure differences between an l2tp socket and an inet socket.
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.
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).
The PV superpage functionality in arch/x86/mm.c in Xen 3.4.0, 3.4.1, and 4.1.x through 4.6.x allows local PV guests to obtain sensitive information, cause a denial of service, gain privileges, or have unspecified other impact via a crafted page identifier (MFN) to the (1) MMUEXT_MARK_SUPER or (2) MMUEXT_UNMARK_SUPER sub-op in the HYPERVISOR_mmuext_op hypercall or (3) unknown vectors related to page table updates.
Integer overflow in the ping_init_sock function in net/ipv4/ping.c in the Linux kernel through 3.14.1 allows local users to cause a denial of service (use-after-free and system crash) or possibly gain privileges via a crafted application that leverages an improperly managed reference counter.
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).
grant table v2 status pages may remain accessible after de-allocation (take two) 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. This bug was fortuitously fixed by code cleanup in Xen 4.14, and backported to security-supported Xen branches as a prerequisite of the fix for XSA-378.