VDB-235026 · CVE-2022-28736 · Nessus 236637

Grub2 chainloader Command grub_cmd_chainloader use after free

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.8	$0-$5k	0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Grub2. Affected by this vulnerability is the function grub_cmd_chainloader of the component chainloader Command Handler. The manipulation results in use after free. This vulnerability is identified as CVE-2022-28736. The attack is only possible with local access. There is not any exploit available. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability classified as critical has been found in Grub2 (affected version unknown). Affected is the function grub_cmd_chainloader of the component chainloader Command Handler. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The weakness was released 07/20/2023. The advisory is available at openwall.com. This vulnerability is traded as CVE-2022-28736 since 04/05/2022. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 236637 (Alibaba Cloud Linux 3 : 0164: grub2, mokutil, shim, and shim-unsigned-x64 (ALINUX3-SA-2022:0164)), which helps to determine the existence of the flaw in a target environment.

Applying a patch is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at Tenable (236637). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

Grub2

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.9
VulDB Meta Temp Score: 6.8

VulDB Base Score: 6.4
VulDB Temp Score: 6.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CNA Base Score: 6.4
CNA Vector (Canonical Ltd.): 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 236637
Nessus Name: Alibaba Cloud Linux 3 : 0164: grub2, mokutil, shim, and shim-unsigned-x64 (ALINUX3-SA-2022:0164)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Timelineinfo

04/05/2022 🔍
07/20/2023 +471 days 🔍
07/20/2023 +0 days 🔍
05/19/2025 +669 days 🔍

Sourcesinfo

Advisory: openwall.com
Status: Confirmed

CVE: CVE-2022-28736 (🔍)
GCVE (CVE): GCVE-0-2022-28736
GCVE (VulDB): GCVE-100-235026

Entryinfo

Created: 07/20/2023 08:45
Updated: 05/19/2025 19:40
Changes: 07/20/2023 08:45 (46), 07/20/2023 08:47 (1), 08/15/2023 08:23 (11), 05/19/2025 19:40 (17)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.