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CVE Record

CVE-2022-28736: There's a use-after-free vulnerability in grub_cmd_chainloader() function

There's a use-after-free vulnerability in grub_cmd_chainloader() function; The chainloader command is used to boot up operating systems that doesn't support multiboot and do not have direct support from GRUB2. When executing chainloader more than once a use-after-free vulnerability is triggered. If an attacker can control the GRUB2's memory allocation pattern sensitive data may be exposed and arbitrary code execution can be achieved.

MediumCVSS 6.4Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2022-28736 is a GRUB2 bootloader flaw in the chainloader command. If a highly privileged local attacker can trigger the command more than once and shape memory allocation, sensitive data exposure or code execution may be possible.

Executive priority

Treat as a moderate-priority infrastructure hardening item. It is not described as remotely exploitable or actively exploited, but bootloader compromise can undermine system trust where privileged access is already possible.

Technical view

The issue is a use-after-free in grub_cmd_chainloader(). The CVSS vector is local, high complexity, high privileges required, no user interaction, with high confidentiality, integrity, and availability impact if exploitation succeeds.

Likely exposure

Exposure is most likely on systems using GNU GRUB/grub2 where privileged users or boot-time operators can access GRUB commands or alter bootloader behavior. The source bundle does not provide specific fixed versions or complete downstream affected-product lists.

Exploitation context

The bundle does not cite CISA KEV listing or active exploitation. Practical exploitation appears constrained by local access, high privileges, and high complexity, but successful exploitation could affect trusted boot flow and host integrity.

Researcher notes

Evidence supports a GRUB2 chainloader use-after-free with severe potential impact but difficult prerequisites. The public bundle lacks precise fixed versions, exploit observations, and detailed downstream product scope, so validation should be vendor-specific.

Mitigation direction

  • Check operating system and appliance vendor advisories for GRUB2 updates addressing CVE-2022-28736.
  • Apply vendor-provided grub2 or bootloader updates when available.
  • Limit administrative and physical access paths to bootloader configuration and console access.
  • Track downstream vendor status, including appliances that package GRUB2 components.

Validation and detection

  • Inventory systems and appliances using GNU GRUB or grub2 packages.
  • Compare installed grub2 versions against vendor security advisories for CVE-2022-28736.
  • Review whether GRUB chainloader functionality is enabled or reachable in operational boot paths.
  • Confirm whether privileged local or boot-console access is tightly controlled.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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.

description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2022-28736 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.4 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
4Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
6.4CVSS 3.1MediumCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H0.55.9Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.4Medium
CVSS 3.1 vector shape for CVE-2022-28736Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
GNU ProjectGNU GRUBgrub2, 0Listed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.