Linux Kernel up to 5.19.16/6.0.2 APIC Interface privilege escalation

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 5.19.16/6.0.2. This affects an unknown function of the component APIC Interface. Performing a manipulation results in an unknown weakness. This vulnerability was named CVE-2022-50720. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.19.16/6.0.2. It has been classified as critical. This affects some unknown functionality of the component APIC Interface. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: x86/apic: Don't disable x2APIC if locked The APIC supports two modes, legacy APIC (or xAPIC), and Extended APIC (or x2APIC). X2APIC mode is mostly compatible with legacy APIC, but it disables the memory-mapped APIC interface in favor of one that uses MSRs. The APIC mode is controlled by the EXT bit in the APIC MSR. The MMIO/xAPIC interface has some problems, most notably the APIC LEAK [1]. This bug allows an attacker to use the APIC MMIO interface to extract data from the SGX enclave. Introduce support for a new feature that will allow the BIOS to lock the APIC in x2APIC mode. If the APIC is locked in x2APIC mode and the kernel tries to disable the APIC or revert to legacy APIC mode a GP fault will occur. Introduce support for a new MSR (IA32_XAPIC_DISABLE_STATUS) and handle the new locked mode when the LEGACY_XAPIC_DISABLED bit is set by preventing the kernel from trying to disable the x2APIC. On platforms with the IA32_XAPIC_DISABLE_STATUS MSR, if SGX or TDX are enabled the LEGACY_XAPIC_DISABLED will be set by the BIOS. If legacy APIC is required, then it SGX and TDX need to be disabled in the BIOS. [1]: https://aepicleak.com/aepicleak.pdf

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2022-50720 since 12/24/2025. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/20/2026).

The vulnerability scanner Nessus provides a plugin with the ID 279765 (Linux Distros Unpatched Vulnerability : CVE-2022-50720), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.19.17 or 6.0.3 eliminates this vulnerability. Applying the patch 05785ba834f23272f9d23427ae4a80ac505a5296/dd1241e00addbf0b95f6cd6ce32152692820657e/b8d1d163604bd1e600b062fb00de5dc42baa355f is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (279765) and CERT Bund (WID-SEC-2025-2929). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.19.0
• 5.19.1
• 5.19.2
• 5.19.3
• 5.19.4
• 5.19.5
• 5.19.6
• 5.19.7
• 5.19.8
• 5.19.9
• 5.19.10
• 5.19.11
• 5.19.12
• 5.19.13
• 5.19.14
• 5.19.15
• 5.19.16
• 6.0.0
• 6.0.1
• 6.0.2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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Entryinfo

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