Buffer overflow in Red Hat Enterprise Linux 7

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.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.054 (92.4th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 92nd percentile — 92.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2023-40547: held from 0.054 to 0.054.

EPSS over last 30 days · oldest: 0.054 · newest: 0.054 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2023-40547?
CVE-2023-40547 is a high-severity vulnerability in Red Hat Enterprise Linux 7, classified under Out-of-bounds Write. CVSS score: 8.3/10. Published 2024-01-25.
How severe is CVE-2023-40547?
High severity. CVSS v3 base score is 8.3 out of 10.
Is CVE-2023-40547 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.