CVE-2023-46841

/// Technical description

Recent x86 CPUs offer functionality named Control-flow Enforcement

Technology (CET). A sub-feature of this are Shadow Stacks (CET-SS).

CET-SS is a hardware feature designed to protect against Return Oriented

Programming attacks. When enabled, traditional stacks holding both data

and return addresses are accompanied by so called "shadow stacks",

holding little more than return addresses. Shadow stacks aren't

writable by normal instructions, and upon function returns their

contents are used to check for possible manipulation of a return address

coming from the traditional stack.

In particular certain memory accesses need intercepting by Xen. In

various cases the necessary emulation involves kind of replaying of

the instruction. Such replaying typically involves filling and then

invoking of a stub. Such a replayed instruction may raise an

exceptions, which is expected and dealt with accordingly.

Unfortunately the interaction of both of the above wasn't right:

Recovery involves remo

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References