An issue was discovered in Xen 4.12.3 through 4.12.4 and 4.13.1 through 4.14.x. An x86 HVM guest with PCI pass through devices can force the allocation of all IDT vectors on the system by rebooting itself with MSI or MSI-X capabilities enabled and entries setup. Such reboots will leak any vectors used by the MSI(-X) entries that the guest might had enabled, and hence will lead to vector exhaustion on the system, not allowing further PCI pass through devices to work properly. HVM guests with PCI pass through devices can mount a Denial of Service (DoS) attack affecting the pass through of PCI devices to other guests or the hardware domain. In the latter case, this would affect the entire host.

The remote host is affected by the vulnerability described in GLSA-202107-30 (Xen: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in Xen. Please review the       CVE identifiers referenced below for details.
  Impact :

    Please review the referenced CVE identifiers for details.
  Workaround :

    There is no known workaround at this time.

The remote SUSE Linux SLES12 / SLES_SAP12 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2021:2955-1 advisory.

  - Observable response discrepancy in some Intel(R) Processors may allow an authorized user to potentially     enable information disclosure via local access. (CVE-2021-0089)

  - A stack overflow via an infinite recursion vulnerability was found in the eepro100 i8255x device emulator     of QEMU. This issue occurs while processing controller commands due to a DMA reentry issue. This flaw     allows a guest user or process to consume CPU cycles or crash the QEMU process on the host, resulting in a     denial of service. The highest threat from this vulnerability is to system availability. (CVE-2021-20255)

  - x86: TSX Async Abort protections not restored after S3 This issue relates to the TSX Async Abort     speculative security vulnerability. Please see https://xenbits.xen.org/xsa/advisory-305.html for details.
    Mitigating TAA by disabling TSX (the default and preferred option) requires selecting a non-default     setting in MSR_TSX_CTRL. This setting isn't restored after S3 suspend. (CVE-2021-28690)

  - inappropriate x86 IOMMU timeout detection / handling IOMMUs process commands issued to them in parallel     with the operation of the CPU(s) issuing such commands. In the current implementation in Xen, asynchronous     notification of the completion of such commands is not used. Instead, the issuing CPU spin-waits for the     completion of the most recently issued command(s). Some of these waiting loops try to apply a timeout to     fail overly-slow commands. The course of action upon a perceived timeout actually being detected is     inappropriate: - on Intel hardware guests which did not originally cause the timeout may be marked as     crashed, - on AMD hardware higher layer callers would not be notified of the issue, making them continue     as if the IOMMU operation succeeded. (CVE-2021-28692)

  - 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). (CVE-2021-28694, CVE-2021-28695, CVE-2021-28696)

  - 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. (CVE-2021-28697)

  - long running loops in grant table handling In order to properly monitor resource use, Xen maintains     information on the grant mappings a domain may create to map grants offered by other domains. In the     process of carrying out certain actions, Xen would iterate over all such entries, including ones which     aren't in use anymore and some which may have been created but never used. If the number of entries for a     given domain is large enough, this iterating of the entire table may tie up a CPU for too long, starving     other domains or causing issues in the hypervisor itself. Note that a domain may map its own grants, i.e.
    there is no need for multiple domains to be involved here. A pair of cooperating guests may, however,     cause the effects to be more severe. (CVE-2021-28698)

  - inadequate grant-v2 status frames array bounds check The v2 grant table interface separates grant     attributes from grant status. That is, when operating in this mode, a guest has two tables. As a result,     guests also need to be able to retrieve the addresses that the new status tracking table can be accessed     through. For 32-bit guests on x86, translation of requests has to occur because the interface structure     layouts commonly differ between 32- and 64-bit. The translation of the request to obtain the frame numbers     of the grant status table involves translating the resulting array of frame numbers. Since the space used     to carry out the translation is limited, the translation layer tells the core function the capacity of the     array within translation space. Unfortunately the core function then only enforces array bounds to be     below 8 times the specified value, and would write past the available space if enough frame numbers needed     storing. (CVE-2021-28699)

  - An issue was discovered in Xen 4.12.3 through 4.12.4 and 4.13.1 through 4.14.x. An x86 HVM guest with PCI     pass through devices can force the allocation of all IDT vectors on the system by rebooting itself with     MSI or MSI-X capabilities enabled and entries setup. Such reboots will leak any vectors used by the     MSI(-X) entries that the guest might had enabled, and hence will lead to vector exhaustion on the system,     not allowing further PCI pass through devices to work properly. HVM guests with PCI pass through devices     can mount a Denial of Service (DoS) attack affecting the pass through of PCI devices to other guests or     the hardware domain. In the latter case, this would affect the entire host. (CVE-2021-3308)

  - An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw     exists in the bootp_input() function and could occur while processing a udp packet that is smaller than     the size of the 'bootp_t' structure. A malicious guest could use this flaw to leak 10 bytes of     uninitialized heap memory from the host. The highest threat from this vulnerability is to data     confidentiality. This flaw affects libslirp versions prior to 4.6.0. (CVE-2021-3592)

  - An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw     exists in the udp_input() function and could occur while processing a udp packet that is smaller than the     size of the 'udphdr' structure. This issue may lead to out-of-bounds read access or indirect host memory     disclosure to the guest. The highest threat from this vulnerability is to data confidentiality. This flaw     affects libslirp versions prior to 4.6.0. (CVE-2021-3594)

  - An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw     exists in the tftp_input() function and could occur while processing a udp packet that is smaller than the     size of the 'tftp_t' structure. This issue may lead to out-of-bounds read access or indirect host memory     disclosure to the guest. The highest threat from this vulnerability is to data confidentiality. This flaw     affects libslirp versions prior to 4.6.0. (CVE-2021-3595)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

This update for xen fixes the following issues :

CVE-2020-28368: Intel RAPL sidechannel attack aka PLATYPUS attack (bsc#1178591, XSA-351)

CVE-2021-3308: IRQ vector leak on x86 (bsc#1181254, XSA-360)

CVE-2021-28687: HVM soft-reset crashes toolstack (bsc#1183072, XSA-368)

L3: conring size for XEN HV's with huge memory to small (bsc#1177204).

kdump of HVM fails, soft-reset not handled by libxl (bsc#1179148)

openQA job causes libvirtd to dump core when running kdump inside domain (bsc#1181989).

Upstream bug fixes (bsc#1027519)

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by a denial of service (DoS) vulnerability. An x86 HVM guest with PCI pass through devices can force the allocation of all IDT vectors on the system by rebooting itself with MSI or MSI-X capabilities enabled and entries setup. Such reboots will leak any vectors used by the MSI(-X) entries that the guest might had enabled, and hence will lead to vector exhaustion on the system, not allowing further PCI pass through devices to work properly. HVM guests with PCI pass through devices can mount a DoS attack affecting the pass through of PCI devices to other guests or the hardware domain. In the latter case, this would affect the entire host.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version   number.

This update for xen fixes the following issues :

  - CVE-2021-3308: VUL-0: xen: IRQ vector leak on x86     (bsc#1181254, XSA-360)

  - CVE-2021-28687: HVM soft-reset crashes toolstack     (bsc#1183072, XSA-368)

  - L3: conring size for XEN HV's with huge memory to small.
    Inital Xen logs cut (bsc#1177204)

  - L3: XEN domU crashed on resume when using the xl unpause     command (bsc#1182576)

  - L3: xen: no needsreboot flag set (bsc#1180690)

  - kdump of HVM fails, soft-reset not handled by libxl     (bsc#1179148)

  - openQA job causes libvirtd to dump core when running     kdump inside domain (bsc#1181989)

  - Upstream bug fixes (bsc#1027519)

This update was imported from the SUSE:SLE-15-SP2:Update update project.

This update for xen fixes the following issues :

CVE-2021-3308: VUL-0: xen: IRQ vector leak on x86 (bsc#1181254, XSA-360)

CVE-2021-28687: HVM soft-reset crashes toolstack (bsc#1183072, XSA-368)

L3: conring size for XEN HV's with huge memory to small. Inital Xen logs cut (bsc#1177204)

L3: XEN domU crashed on resume when using the xl unpause command (bsc#1182576)

L3: xen: no needsreboot flag set (bsc#1180690)

kdump of HVM fails, soft-reset not handled by libxl (bsc#1179148)

openQA job causes libvirtd to dump core when running kdump inside domain (bsc#1181989)

Upstream bug fixes (bsc#1027519)

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This update for xen fixes the following issues :

CVE-2021-3308: VUL-0: xen: IRQ vector leak on x86 (bsc#1181254, XSA-360)

CVE-2021-28687: VUL-0: xen: HVM soft-reset crashes toolstack (bsc#1183072, XSA-368)

CVE-2021-20257: VUL-0: xen: infinite loop issue in the e1000 NIC emulator (bsc#1182846)

CVE-2020-28368: VUL-0: xen: Intel RAPL sidechannel attack aka PLATYPUS attack aka (bsc#1178591, XSA-351)

L3: conring size for XEN HV's with huge memory to small. Inital Xen logs cut (bsc#1177204)

Kdump of HVM fails, soft-reset not handled by libxl (bsc#1179148)

OpenQA job causes libvirtd to dump core when running kdump inside domain (bsc#1181989)

Allow restart of xenwatchdogd, enable tuning of keep-alive interval and timeout options via XENWATCHDOGD_ARGS= (bsc#1178736)

The receiving side did detect holes in a to-be-allocated superpage, but allocated a superpage anyway. This resulted to over-allocation (bsc#1177112)

The receiving side may punch holes incorrectly into optimistically allocated superpages. Also reduce overhead in bitmap handling (bsc#1177112)

Upstream bug fixes (bsc#1027519)

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

The remote Fedora 32 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2021-16c9c40d4d advisory.

  - An issue was discovered in Xen 4.12.3 through 4.12.4 and 4.13.1 through 4.14.x. An x86 HVM guest with PCI     pass through devices can force the allocation of all IDT vectors on the system by rebooting itself with     MSI or MSI-X capabilities enabled and entries setup. Such reboots will leak any vectors used by the     MSI(-X) entries that the guest might had enabled, and hence will lead to vector exhaustion on the system,     not allowing further PCI pass through devices to work properly. HVM guests with PCI pass through devices     can mount a Denial of Service (DoS) attack affecting the pass through of PCI devices to other guests or     the hardware domain. In the latter case, this would affect the entire host. (CVE-2021-3308)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
157004	GLSA-202107-30 : Xen: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high
152991	SUSE SLES12 Security Update : xen (SUSE-SU-2021:2955-1)	Nessus	SuSE Local Security Checks	high
149227	SUSE SLES15 Security Update : xen (SUSE-SU-2021:1460-1)	Nessus	SuSE Local Security Checks	medium
149086	Xen IRQ Vector Leak DoS (XSA-360)	Nessus	Misc.	medium
148384	openSUSE Security Update : xen (openSUSE-2021-514)	Nessus	SuSE Local Security Checks	medium
148366	SUSE SLED15 / SLES15 Security Update : xen (SUSE-SU-2021:1028-1)	Nessus	SuSE Local Security Checks	medium
148365	SUSE SLES12 Security Update : xen (SUSE-SU-2021:1023-1)	Nessus	SuSE Local Security Checks	medium
145769	Fedora 32 : xen (2021-16c9c40d4d)	Nessus	Fedora Local Security Checks	medium

Detections

Analytics

CVE-2021-3308

medium

Tenable Plugins

high

high

medium

medium

medium

medium

medium

medium