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CentOS 7 : shim (RHSA-2024:1959)

high Nessus Plugin ID 193955

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Synopsis

The remote CentOS Linux host is missing one or more security updates.

Description

The remote CentOS Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2024:1959 advisory.

 - 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-2023-40546)

 - 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.
 (CVE-2023-40547)

 - 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-2023-40548)

 - 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-2023-40549)

 - 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-2023-40550)

 - 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-2023-40551)

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.

See Also

https://access.redhat.com/errata/RHSA-2024:1959

Plugin Details

Severity: High

ID: 193955

File Name: centos_RHSA-2024-1959.nasl

Version: 1.0

Type: local

Agent: unix

Published: 4/26/2024

Updated: 4/26/2024

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Critical

Score: 9.2

Vendor

Vendor Severity: Important

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: p-cpe:/a:centos:centos:shim-unsigned-ia32, cpe:/o:centos:centos:7, p-cpe:/a:centos:centos:shim-x64, p-cpe:/a:centos:centos:mokutil, p-cpe:/a:centos:centos:shim-unsigned-x64, p-cpe:/a:centos:centos:shim-ia32

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/CentOS/release, Host/CentOS/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 4/23/2024

Vulnerability Publication Date: 12/11/2023

Reference Information

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

RHSA: 2024:1959