#VU86237 Integer overflow in Shim - CVE-2023-40548

Vulnerability identifier: #VU86237

Vulnerability risk: Medium

CVSSv4.0: 4.8 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-40548

CWE-ID: CWE-190

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Shim
Universal components / Libraries / Libraries used by multiple products

Vendor: Red Hat Bootloader Team

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to integer overflow within the verify_sbat_section on 32-bits systems. A remote attacker can pass a specially crafted PE binary to the application, trigger an integer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Shim: 0.3 - 15.7

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External links
https://access.redhat.com/security/cve/CVE-2023-40548
https://bugzilla.redhat.com/show_bug.cgi?id=2241782

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.