Das U-Boot up to 2021.04-rc1 Boot Loader Local Privilege Escalation

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.
6.7$0-$5k0.00

Summaryinfo

A vulnerability was found in Das U-Boot up to 2021.04-rc1 and classified as problematic. The affected element is an unknown function of the component Boot Loader. Such manipulation leads to an unknown weakness. This vulnerability is uniquely identified as CVE-2021-27138. Local access is required to approach this attack. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Das U-Boot up to 2021.04-rc1 and classified as problematic. Affected by this issue is an unknown code of the component Boot Loader. Impacted is confidentiality, integrity, and availability.

The weakness was disclosed 02/18/2021 as 3f04db891a353f4b127ed57279279f851c6b4917. The advisory is shared for download at github.com. This vulnerability is handled as CVE-2021-27138. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 266339 (Debian dla-4320 : u-boot - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2021.04-rc2 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (266339). Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.8
VulDB Meta Temp Score: 6.7

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CNA Base Score: 7.8
CNA Vector (MITRE): 🔍

CVSSv2info

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

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

NVD Base Score: 🔍

Exploitinginfo

Class: Local Privilege Escalation
CWE: Unknown
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 266339
Nessus Name: Debian dla-4320 : u-boot - security update

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Das U-Boot 2021.04-rc2
Patch: github.com

Timelineinfo

02/10/2021 🔍
02/18/2021 +8 days 🔍
02/18/2021 +0 days 🔍
11/03/2025 +1719 days 🔍

Sourcesinfo

Advisory: 3f04db891a353f4b127ed57279279f851c6b4917
Status: Confirmed

CVE: CVE-2021-27138 (🔍)
GCVE (CVE): GCVE-0-2021-27138
GCVE (VulDB): GCVE-100-170132

Entryinfo

Created: 02/18/2021 07:55
Updated: 11/03/2025 22:53
Changes: 02/18/2021 07:55 (37), 03/03/2021 10:09 (5), 03/03/2021 10:13 (8), 10/02/2025 13:04 (17), 11/03/2025 22:53 (21)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Interested in the pricing of exploits?

See the underground prices here!