TencentOS Server 4: shim (TSSA-2024:0566)

high Nessus Plugin ID 238838

Synopsis

The remote TencentOS Server 4 host is missing one or more security updates.

Description

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the TSSA-2024:0566 advisory.

Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

CVE-2023-40551:
A flaw was found in the MZ binary format in Shim. An out-of-bounds read may occur, leading to a crash or possible exposure of sensitive data during the system's boot phase.

CVE-2023-40549:
An out-of-bounds read flaw was found in Shim due to the lack of proper boundary verification during the load of a PE binary. This flaw allows an attacker to load a crafted PE binary, triggering the issue and crashing Shim, resulting in a denial of service.

CVE-2023-40546:
A flaw was found in Shim when an error happened while creating a new ESL variable. If Shim fails to create the new variable, it tries to print an error message to the user; however, the number of parameters used by the logging function doesn't match the format string used by it, leading to a crash under certain circumstances.

CVE-2023-40550:
An out-of-bounds read flaw was found in Shim when it tried to validate the SBAT information. This issue may expose sensitive data during the system's boot phase.

CVE-2023-40548:
A buffer overflow was found in Shim in the 32-bit system. The overflow happens due to an addition operation involving a user-controlled value parsed from the PE binary being used by Shim. This value is further used for memory allocation operations, leading to a heap-based buffer overflow. This flaw causes memory corruption and can lead to a crash or data integrity issues during the boot phase.

CVE-2023-40547:
A remote code execution vulnerability was found in Shim. The Shim boot support trusts attacker-controlled values when parsing an HTTP response. This flaw allows an attacker to craft a specific malicious HTTP request, leading to a completely controlled out-of-bounds write primitive and complete system compromise.
This flaw is only exploitable during the early boot phase, an attacker needs to perform a Man-in-the- Middle or compromise the boot server to be able to exploit this vulnerability successfully.

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

Plugin Details

Severity: High

ID: 238838

File Name: tencentos_TSSA_2024_0566.nasl

Version: 1.2

Type: local

Family: Tencent Local Security Checks

Published: 6/16/2025

Updated: 11/20/2025

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 8.1

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

Vector: CVSS2#AV:A/AC:H/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2023-40547

CVSS v3

Risk Factor: High

Base Score: 8.3

Temporal Score: 7.2

Vector: CVSS:3.0/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:tencent:tencentos_server:4, p-cpe:/a:tencent:tencentos_server:shim

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/etc/os-release, Host/TencentOS/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 10/18/2024

Vulnerability Publication Date: 10/18/2024

Reference Information

CVE: CVE-2023-40546, CVE-2023-40547, CVE-2023-40548, CVE-2023-40549, CVE-2023-40550, CVE-2023-40551

Detections

Analytics