Memory corruption via IPv4 fragment length underflow
Published Jul 20, 2023 · Updated Feb 13, 2025
Integer underflow in GNU GRUB before 2.06-3 allows remote attackers to corrupt memory via crafted fragmented IPv4 packets. grub_net_recv_ip4_packets subtracts fragment offsets from rsm->total_len without first validating the result, allowing the length to wrap to a small allocation before later fragment handling writes beyond the buffer. The attack requires GRUB networking to process a malicious fragment sequence during boot; successful exploitation corrupts boot-loader memory.
Summary
What happened
Integer underflow in GNU GRUB before 2.06-3 allows remote attackers to corrupt memory via crafted fragmented IPv4 packets. grub_net_recv_ip4_packets subtracts fragment offsets from rsm->total_len without first validating the result, allowing the length to wrap to a small allocation before later fragment handling writes beyond the buffer. The attack requires GRUB networking to process a malicious fragment sequence during boot; successful exploitation corrupts boot-loader memory.
The record
- CVE
- CVE-2022-28733
- Published
- Jul 20, 2023
- Updated
- Feb 13, 2025
- Vendor
- The GnuPG Project
- Product
- GNU GRUB
- Classifications
- CWE-191
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 20, 2023CVE publishedPublication date reported by the CVE source.
- Feb 13, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <2.06-3
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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