Mishandling of guest SSBD selection on AMD hardware The current logic to set SSBD on AMD Family 17h and Hygon Family 18h processors requires that the setting of SSBD is coordinated at a core level, as the setting is shared between threads. Logic was introduced to keep track of how many threads require SSBD active in order to coordinate it, such logic relies on using a per-core counter of threads that have SSBD active. When running on the mentioned hardware, it's possible for a guest to under or overflow the thread counter, because each write to VIRT_SPEC_CTRL.SSBD by the guest gets propagated to the helper that does the per-core active accounting. Underflowing the counter causes the value to get saturated, and thus attempts for guests running on the same core to set SSBD won't have effect because the hypervisor assumes it's already active.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Mishandling of guest SSBD selection on AMD hardware The current logic to set SSBD on AMD Family 17h and     Hygon Family 18h processors requires that the setting of SSBD is coordinated at a core level, as the     setting is shared between threads. Logic was introduced to keep track of how many threads require SSBD     active in order to coordinate it, such logic relies on using a per-core counter of threads that have SSBD     active. When running on the mentioned hardware, it's possible for a guest to under or overflow the thread     counter, because each write to VIRT_SPEC_CTRL.SSBD by the guest gets propagated to the helper that does     the per-core active accounting. Underflowing the counter causes the value to get saturated, and thus     attempts for guests running on the same core to set SSBD won't have effect because the hypervisor assumes     it's already active. (CVE-2022-42336)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - Mishandling of guest SSBD selection on AMD hardware The current logic to set SSBD on AMD Family 17h and
    Hygon Family 18h processors requires that the setting of SSBD is coordinated at a core level, as the
    setting is shared between threads. Logic was introduced to keep track of how many threads require SSBD
    active in order to coordinate it, such logic relies on using a per-core counter of threads that have SSBD
    active. When running on the mentioned hardware, it's possible for a guest to under or overflow the thread
    counter, because each write to VIRT_SPEC_CTRL.SSBD by the guest gets propagated to the helper that does
    the per-core active accounting. Underflowing the counter causes the value to get saturated, and thus
    attempts for guests running on the same core to set SSBD won't have effect because the hypervisor assumes
    it's already active. (CVE-2022-42336)

The remote host is affected by the vulnerability described in GLSA-202409-10 (Xen: Multiple Vulnerabilities)

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

Tenable has extracted the preceding description block directly from the Gentoo Linux security advisory.

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

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 / openSUSE 15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2023:2535-1 advisory.

    Security fixes:

    - CVE-2022-42336: Fix an issue where guests configuring AMD       Speculative Store Bypass Disable would have no effect (XSA-431)       (bsc#1211433).
    - CVE-2022-42335: Fixed an issue where guests running under shadow       mode with a PCI devices passed through could force the hypervisor       to dereference arbitrary memory, leading to a denial of service       (XSA-430) (bsc#1210315).

    Non-security fixes:

    - Fixed a build warning false positive (bsc#1210570).
    - Added missing debug-info to xen-syms (bsc#1209237).
    - Updated to version 4.17.1 (bsc#1027519).
    - Fixed a failure during VM destruction when using host-assisted kexec       and kdump (bsc#1209245).
    - Other upstream fixes (bsc#1027519).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

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

The remote Fedora 38 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2023-8334fe0ecb advisory.

    Mishandling of guest SSBD selection on AMD hardware     [XSA-431, CVE-2022-42336]


Tenable has extracted the preceding description block directly from the Fedora security advisory.

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

ID	Name	Product	Family	Severity
256835	Linux Distros Unpatched Vulnerability : CVE-2022-42336	Nessus	Misc.	low
424730	Alpine: multiple xen packages: security update to 4.17.1-r1	Tenable Cloud Security	Alpine Linux Local Security Checks	low
424730	Alpine: multiple xen packages: security update to 4.17.1-r1	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	low
207559	GLSA-202409-10 : Xen: Multiple Vulnerabilities	Nessus	Gentoo Local Security Checks	high
177438	SUSE SLED15: xen / xen-devel / xen-doc-html / xen-libs / xen-libs-32bit / etc (SUSE-SU-2023:2535-1)	Nessus	SuSE Local Security Checks	high
176428	Fedora 38 : xen (2023-8334fe0ecb)	Nessus	Fedora Local Security Checks	low

Detections

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CVE-2022-42336

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Tenable Plugins

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