grub2 up to 2.11 JPEG Reader out-of-bounds write

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.
6.9$0-$5k0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in grub2 up to 2.11. Impacted is an unknown function of the component JPEG Reader. The manipulation results in out-of-bounds write. This vulnerability is cataloged as CVE-2021-3697. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in grub2 up to 2.11. Affected is an unknown functionality of the component JPEG Reader. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. CWE is classifying the issue as CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

A crafted JPEG image may lead the JPEG reader to underflow its data pointer, allowing user-controlled data to be written in heap. To a successful to be performed the attacker needs to perform some triage over the heap layout and craft an image with a malicious format and payload. This vulnerability can lead to data corruption and eventual code execution or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.

The weakness was shared 07/06/2022. The advisory is available at bugzilla.redhat.com. This vulnerability is traded as CVE-2021-3697 since 08/10/2021. The technical details are unknown and an exploit is not available.

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.

Upgrading to version 2.12 eliminates this vulnerability.

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

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.1
VulDB Meta Temp Score: 6.9

VulDB Base Score: 7.1
VulDB Temp Score: 6.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.0
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

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: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: grub2 2.12

Timelineinfo

08/10/2021 🔍
07/06/2022 +330 days 🔍
07/06/2022 +0 days 🔍
05/19/2025 +1048 days 🔍

Sourcesinfo

Advisory: bugzilla.redhat.com
Status: Confirmed

CVE: CVE-2021-3697 (🔍)
GCVE (CVE): GCVE-0-2021-3697
GCVE (VulDB): GCVE-100-203274

Entryinfo

Created: 07/06/2022 21:43
Updated: 05/19/2025 19:40
Changes: 07/06/2022 21:43 (39), 07/19/2022 13:16 (17), 05/19/2025 19:40 (16)
Complete: 🔍
Cache ID: 216::103

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

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Interested in the pricing of exploits?

See the underground prices here!