How severe is CVE-2022-28733?

CVE-2022-28733 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2022-28733 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2022-28733?

CVE-2022-28733 affects Gnu Grub2. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2022-28733?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2022-28733 published?

CVE-2022-28733 was published on 2023-07-20 and last updated on 2026-06-17.

CVE-2022-28733

CVE-2022-28733 is a high-severity vulnerability in Gnu Grub2 with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-191.

Key facts

Severity: High (CVSS 3.x base score 8.1)
EPSS exploit prediction: 1% (67th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-191
Affected product: Gnu Grub2
Published: 2023-07-20
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2022-28733?: 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.
How severe is CVE-2022-28733?: CVE-2022-28733 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2022-28733 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2022-28733?: CVE-2022-28733 affects Gnu Grub2. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2022-28733?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2022-28733 published?: CVE-2022-28733 was published on 2023-07-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*

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