CVE-2023-40547
8.3
HIGH
CVSS 3.1
EPSS 3.8%
Description
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.
How to fix CVE-2023-40547
To remediate CVE-2023-40547, upgrade the affected package to a fixed version below.
- —upgrade to 15.8-1~deb11u1 or later
Is CVE-2023-40547 being exploited?
Low — EPSS is 3.8%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 15.8-1~deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH8.3 | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H |