// For flags

CVE-2022-28736

There's a use-after-free vulnerability in grub_cmd_chainloader() function

Severity Score

7.8
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track*
*SSVC
Descriptions

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.

A use-after-free vulnerability was found on grub2's chainloader command. This flaw allows an attacker to gain access to restricted data or cause arbitrary code execution if they can establish control from grub's memory allocation pattern.

An update that solves 7 vulnerabilities and has three fixes is now available. This update for grub2 fixes the following issues. This update provides security fixes and hardenings for Boothole 3 / Boothole 2022. Fixed that a crafted PNG grayscale image could lead to out-of-bounds write in heap. Fixed that a crafted PNG image could lead to out-of-bound write during huffman table handling. Fixed that a crafted JPEG image could lead to buffer underflow write in the heap. Fixed fragmentation math in net/ip. Fixed an out-of-bound write for split http headers. Fixed some verifier framework changes. Fixed a use-after-free in chainloader command LV is completely in the boot LUN.

*Credits: Chris Coulson
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Local
Attack Complexity
High
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Local
Attack Complexity
Low
Authentication
Single
Confidentiality
Complete
Integrity
Complete
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:Track*
Exploitation
None
Automatable
No
Tech. Impact
Total
* Organization's Worst-case Scenario
Timeline
  • 2022-04-05 CVE Reserved
  • 2022-06-10 CVE Published
  • 2025-02-13 CVE Updated
  • 2025-08-11 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-416: Use After Free
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Gnu
Search vendor "Gnu"
 Grub2
Search vendor "Gnu" for product "Grub2"
 >= 2.00 < 2.06-3
Search vendor "Gnu" for product "Grub2" and version " >= 2.00 < 2.06-3"
-
Affected