Xen on AMD SSBD integer overflow

Summaryinfo

A vulnerability categorized as problematic has been discovered in Xen on AMD. The affected element is an unknown function of the component SSBD Handler. Such manipulation leads to integer overflow. This vulnerability is uniquely identified as CVE-2022-42336. No exploit exists. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability was found in Xen on AMD (Virtualization Software) (affected version unknown). It has been rated as problematic. Affected by this issue is an unknown functionality of the component SSBD Handler. The manipulation with an unknown input leads to a integer overflow vulnerability. Using CWE to declare the problem leads to CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. The impact remains unknown. CVE summarizes:

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 weakness was disclosed 05/17/2023. The advisory is available at xenbits.xenproject.org. This vulnerability is handled as CVE-2022-42336 since 10/03/2022. The technical details are unknown and an exploit is not available.

Applying a patch is able to eliminate this problem.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Virtualization Software

Name

• Xen

License

• open-source

CPE 2.3info

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• 🔍

CPE 2.2info

• 🔍
• 🔍

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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