172 results (0.002 seconds)

CVSS: 3.3EPSS: 0%CPEs: 1EXPL: 0

05 Jan 2024 — Arm provides multiple helpers to clean & invalidate the cache for a given region. This is, for instance, used when allocating guest memory to ensure any writes (such as the ones during scrubbing) have reached memory before handing over the page to a guest. Unfortunately, the arithmetics in the helpers can overflow and would then result to skip the cache cleaning/invalidation. Therefore there is no guarantee when all the writes will reach the memory. This undefined behavior was meant to be addressed by XSA-4... • https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JFVKWYQFRUU3CAS53THTUKXEOUDWI42G • CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer •

CVSS: 5.5EPSS: 0%CPEs: 1EXPL: 0

05 Jan 2024 — When a transaction is committed, C Xenstored will first check the quota is correct before attempting to commit any nodes. It would be possible that accounting is temporarily negative if a node has been removed outside of the transaction. Unfortunately, some versions of C Xenstored are assuming that the quota cannot be negative and are using assert() to confirm it. This will lead to C Xenstored crash when tools are built without -DNDEBUG (this is the default). Cuando se confirma una transacción, C Xenstored ... • https://xenbits.xenproject.org/xsa/advisory-440.html • CWE-476: NULL Pointer Dereference •

CVSS: 7.8EPSS: 0%CPEs: 1EXPL: 0

05 Jan 2024 — For migration as well as to work around kernels unaware of L1TF (see XSA-273), PV guests may be run in shadow paging mode. Since Xen itself needs to be mapped when PV guests run, Xen and shadowed PV guests run directly the respective shadow page tables. For 64-bit PV guests this means running on the shadow of the guest root page table. In the course of dealing with shortage of memory in the shadow pool associated with a domain, shadows of page tables may be torn down. This tearing down may include the shado... • https://xenbits.xenproject.org/xsa/advisory-438.html • CWE-273: Improper Check for Dropped Privileges •

CVSS: 3.3EPSS: 0%CPEs: 1EXPL: 0

05 Jan 2024 — Arm provides multiple helpers to clean & invalidate the cache for a given region. This is, for instance, used when allocating guest memory to ensure any writes (such as the ones during scrubbing) have reached memory before handing over the page to a guest. Unfortunately, the arithmetics in the helpers can overflow and would then result to skip the cache cleaning/invalidation. Therefore there is no guarantee when all the writes will reach the memory. Arm proporciona múltiples ayudas para limpiar e invalidar ... • https://xenbits.xenproject.org/xsa/advisory-437.html • CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer •

CVSS: 5.5EPSS: 0%CPEs: 4EXPL: 0

25 Jan 2022 — A PV guest could DoS Xen while unmapping a grant To address XSA-380, reference counting was introduced for grant mappings for the case where a PV guest would have the IOMMU enabled. PV guests can request two forms of mappings. When both are in use for any individual mapping, unmapping of such a mapping can be requested in two steps. The reference count for such a mapping would then mistakenly be decremented twice. Underflow of the counters gets detected, resulting in the triggering of a hypervisor bug check... • http://www.openwall.com/lists/oss-security/2022/01/25/3 • CWE-191: Integer Underflow (Wrap or Wraparound) •

CVSS: 7.0EPSS: 0%CPEs: 1EXPL: 0

07 Dec 2021 — 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 re... • https://security.gentoo.org/glsa/202402-07 •

CVSS: 8.6EPSS: 0%CPEs: 4EXPL: 0

24 Nov 2021 — guests may exceed their designated memory limit When a guest is permitted to have close to 16TiB of memory, it may be able to issue hypercalls to increase its memory allocation beyond the administrator established limit. This is a result of a calculation done with 32-bit precision, which may overflow. It would then only be the overflowed (and hence small) number which gets compared against the established upper bound. Los huéspedes pueden exceder su límite de memoria designado Cuando a un huésped se le perm... • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT • CWE-770: Allocation of Resources Without Limits or Throttling •

CVSS: 5.5EPSS: 0%CPEs: 1EXPL: 0

11 Jun 2021 — x86: Speculative vulnerabilities with bare (non-shim) 32-bit PV guests 32-bit x86 PV guest kernels run in ring 1. At the time when Xen was developed, this area of the i386 architecture was rarely used, which is why Xen was able to use it to implement paravirtualisation, Xen's novel approach to virtualization. In AMD64, Xen had to use a different implementation approach, so Xen does not use ring 1 to support 64-bit guests. With the focus now being on 64-bit systems, and the availability of explicit hardware ... • https://xenbits.xenproject.org/xsa/advisory-370.txt • CWE-212: Improper Removal of Sensitive Information Before Storage or Transfer •

CVSS: 7.8EPSS: 0%CPEs: 2EXPL: 0

18 Feb 2021 — An issue was discovered in Xen through 4.11.x, allowing x86 Intel HVM guest OS users to achieve unintended read/write DMA access, and possibly cause a denial of service (host OS crash) or gain privileges. This occurs because a backport missed a flush, and thus IOMMU updates were not always correct. NOTE: this issue exists because of an incomplete fix for CVE-2020-15565. Se detectó un problema en Xen versiones hasta 4.11.x, permitiendo a usuarios del Sistema Operativo invitado x86 Intel HVM obtener acceso DM... • http://www.openwall.com/lists/oss-security/2021/02/23/1 •

CVSS: 6.0EPSS: 0%CPEs: 4EXPL: 0

15 Dec 2020 — An issue was discovered in Xen through 4.14.x. Nodes in xenstore have an ownership. In oxenstored, a owner could give a node away. However, node ownership has quota implications. Any guest can run another guest out of quota, or create an unbounded number of nodes owned by dom0, thus running xenstored out of memory A malicious guest administrator can cause a denial of service against a specific guest or against the whole host. • https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA • CWE-770: Allocation of Resources Without Limits or Throttling •