Security readout for executives and security teams
Plain-English summary
CVE-2022-28733 is a high-severity memory corruption flaw in GNU GRUB's IPv4 packet handling. A crafted network packet can cause an integer underflow, leading to an undersized allocation and potential overwrite beyond the buffer. Successful exploitation could affect confidentiality, integrity, and availability, but the CVSS vector marks exploitation complexity as high.
Executive priority
Treat this as high priority for infrastructure and appliance teams, especially where network boot is used. The business risk is serious memory corruption before the operating system fully loads, but available evidence does not show confirmed active exploitation in the supplied sources.
Technical view
The issue is a CWE-191 integer underflow in grub_net_recv_ip4_packets(). The rsm->total_len value can wrap to a small integer used for allocation, after which later processing may write past the allocated buffer. The source bundle identifies GNU GRUB/grub2, but does not provide a precise affected version range beyond the supplied record.
Likely exposure
Exposure is most relevant where GNU GRUB/grub2 processes network IPv4 packets during boot or pre-boot operations. The provided sources do not identify specific distributions, appliance models, or fixed vulnerable version ranges, so asset owners should validate against their vendor advisories.
Exploitation context
The CVSS vector is network, no privileges, no user interaction, high complexity, with high confidentiality, integrity, and availability impact. The source bundle does not show CISA KEV listing or any cited evidence of active exploitation, so active exploitation should not be assumed.
Researcher notes
The record supports the bug class, affected component, and impact path, but not exact vulnerable versions, exploit reliability, or patch identifiers. Validation should focus on vendor-specific GRUB package lineage and whether network packet processing is reachable in the target boot configuration.
Mitigation direction
- Check GNU, Linux distribution, appliance, and NetApp advisories for fixed GRUB/grub2 guidance.
- Prioritize vendor-approved bootloader updates for systems using GRUB network functionality.
- Review whether exposed pre-boot network paths are required until vendor guidance is applied.
- Track compensating controls through change management because bootloader updates can carry operational risk.
Validation and detection
- Inventory systems and appliances using GNU GRUB or grub2.
- Identify systems where GRUB network boot or IPv4 packet handling may be enabled.
- Compare installed GRUB/grub2 builds against vendor security advisories.
- Confirm remediation using vendor package metadata or appliance advisory status.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-191: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2022-28733 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H2.25.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.1HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.openwall.com/lists/oss-security/2022/06/07/5CVE reference · mailing-list
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-28733CVE reference · issue-tracking
- https://security.netapp.com/advisory/ntap-20230825-0002/CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Integer Underflow (Wrap or Wraparound)
Integer Underflow (Wrap or Wraparound) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.