Synopsis
The remote Red Hat host is missing one or more security updates for shim.
Description
The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2024:2086 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 RHEL shim package based on the guidance in RHSA-2024:2086.
Plugin Details
File Name: redhat-RHSA-2024-2086.nasl
Agent: unix
Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus
Risk Information
Vector: CVSS2#AV:A/AC:H/Au:N/C:C/I:C/A:C
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:redhat:rhel_aus:8.6, cpe:/o:redhat:rhel_e4s:8.6, cpe:/o:redhat:rhel_eus:8.6, cpe:/o:redhat:rhel_tus:8.6, p-cpe:/a:redhat:enterprise_linux:shim-aa64, p-cpe:/a:redhat:enterprise_linux:shim-ia32, p-cpe:/a:redhat:enterprise_linux:shim-x64
Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu
Exploit Ease: No known exploits are available
Patch Publication Date: 4/29/2024
Vulnerability Publication Date: 12/11/2023