CVE-2023-3161 — A flaw was found in the Framebuffer Console (fbcon) in the Linux Kernel

A flaw was found in the Framebuffer Console (fbcon) in the Linux Kernel. When providing font->width and font->height greater than 32 to fbcon_set_font, since there are no checks in place, a shift-out-of-bounds occurs leading to undefined behavior and possible denial of serv

01What is this vulnerability?

A flaw was found in the Framebuffer Console (fbcon) in the Linux Kernel. When providing font->width and font->height greater than 32 to fbcon_set_font, since there are no checks in place, a shift-out-of-bounds occurs leading to undefined behavior and possible denial of service.

02Affected products

Vendor	Product	Versions
n	a / Linux Kernel (fbcon)	Fixed in kernel 6.2-rc7

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-06-12T00:00:00.000Z
• Last modified: 2025-03-11T14:54:29.577Z

09References

• bugzilla.redhat.com — https://bugzilla.redhat.com/show_bug.cgi?id=2213485
• github.com — https://github.com/torvalds/linux/commit/2b09d5d364986f724f17001ccfe4126b9b43a0b…