Distribution advisory
This page covers CVE-2023-4693 as tracked by Ubuntu, for the package grub2-signed. The fix is available in version 1.199; earlier versions remain affected.
How this vulnerability can be exploited
This issue can be reached with physical access to the device, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity none, availability none.
CVSS metrics in full
The score comes from this vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Attack vector: Physical — the attacker has to touch the device.
- Attack complexity: Low — the attack works reliably, with no preparation.
- Privileges required: None — an unauthenticated stranger can try it.
- User interaction: None — nobody has to be tricked into anything.
- Scope: Unchanged — the damage stays inside the vulnerable component.
- Confidentiality impact: High — total loss, or loss the attacker controls.
- Integrity impact: None.
- Availability impact: None.
Weakness class
UBUNTU-CVE-2023-4693 is classified as CWE-125: Out-of-bounds Read. The code reads past the limits of a buffer, exposing adjacent memory contents or crashing the process.
Affected software
UBUNTU-CVE-2023-4693 is recorded against 2 packages.
- grub2-signed (fixed in 1.199)
- grub2-unsigned (fixed in 2.06-2ubuntu14.4)
Timeline and source
Published on 3 October 2023 and last revised on 4 February 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
ubuntu.com (Report)
lists.gnu.org (Report)
ubuntu.com (Advisory)
dfir.ru (Report)
www.cve.org (Report)
Other advisories for this package
grub2-signed has other advisories on record. If you are patching this one, these are worth checking on the same host:
Same weakness in other software
These advisories are the same class of weakness (CWE-125: Out-of-bounds Read) in other software:
