CVE-2012-3494

What it is

The set_debugreg hypercall in include/asm-x86/debugreg.h in Xen 4.0, 4.1, and 4.2, and Citrix XenServer 6.0.2 and earlier, when running on x86-64 systems, allows local OS guest users to cause a denial of service (host crash) by writing to the reserved bits of the DR7 debug control register.

At a glance

Exploitability

Can be exploited locally on the machine without logging in. Limited direct impact.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2012-11-23 20:55 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-16 23:43 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.4% in the next 30 days (EPSS).
• Severity: 2.1 LOW (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2012-11-23 20:55 UTC

Last modified

2026-06-16 23:43 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-264

Record status

Modified

Affected

• Citrix Xenserver ≤ 6.0.2
• Xen 4.0.0
• Xen 4.1.0
• Xen 4.2.0

Attack profile CVSS 2.0 · 2.1

Attack vector

Local

Complexity

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Partial

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2012-3494.md and follow it. Check whether this project is affected by CVE-2012-3494. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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