VDB-251930 · CVE-2023-40550 · EUVD-2023-45121

rhboot shim verify_buffer_sbat out-of-bounds

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.
4.8	$0-$5k	0.00

Summaryinfo

A vulnerability classified as problematic was found in rhboot shim. This affects the function verify_buffer_sbat. Such manipulation leads to out-of-bounds. This vulnerability is referenced as CVE-2023-40550. No exploit is available.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in rhboot shim (version unknown). Affected by this issue is the function verify_buffer_sbat. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality.

The weakness was published 01/24/2024. The advisory is available at bugzilla.redhat.com. This vulnerability is handled as CVE-2023-40550 since 08/15/2023. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 215335 (Azure Linux 3.0 Security Update: shim / shim-unsigned-aarch64 / shim-unsigned-x64 (CVE-2023-40550)), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at Tenable (215335) and EUVD (EUVD-2023-45121). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

rhboot

Name

shim

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.8
VulDB Meta Temp Score: 4.8

VulDB Base Score: 3.5
VulDB Temp Score: 3.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CNA Base Score: 5.5
CNA Vector (Red Hat, Inc.): 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / 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-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 215335
Nessus Name: Azure Linux 3.0 Security Update: shim / shim-unsigned-aarch64 / shim-unsigned-x64 (CVE-2023-40550)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

08/15/2023 🔍
01/24/2024 +162 days 🔍
01/24/2024 +0 days 🔍
10/01/2025 +616 days 🔍

Sourcesinfo

Advisory: bugzilla.redhat.com
Status: Not defined

CVE: CVE-2023-40550 (🔍)
GCVE (CVE): GCVE-0-2023-40550
GCVE (VulDB): GCVE-100-251930
EUVD: 🔍

Entryinfo

Created: 01/24/2024 09:45
Updated: 10/01/2025 12:37
Changes: 01/24/2024 09:45 (36), 02/17/2024 18:44 (1), 02/17/2024 18:51 (12), 06/11/2024 06:12 (26), 02/11/2025 04:11 (3), 10/01/2025 12:37 (1)
Complete: 🔍
Cache ID: 216::103

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