CVE-2021-3695
What it is
A crafted 16-bit grayscale PNG image may lead to a out-of-bounds write in the heap area. An attacker may take advantage of that to cause heap data corruption or eventually arbitrary code execution and circumvent secure boot protections. This issue has a high complexity to be exploited as an attacker needs to perform some triage over the heap layout to achieve signifcant results, also the values written into the memory are repeated three times in a row making difficult to produce valid payloads. This flaw affects grub2 versions prior grub-2.12.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. Limited direct impact.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.5% in the next 30 days (EPSS).
- Severity: 4.5 MEDIUM (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Weakness
- CWE-787 · Out-of-bounds write
- Record status
- Modified
Affected
- Gnu grub2 < 2.12
- Fedoraproject Fedora 36
- Redhat Developer Tools 1.0
- Redhat Openshift 3.0
- Redhat Enterprise Linux 8.0
- Redhat Enterprise Linux 8.1
- Redhat Enterprise Linux 8.4
- Redhat Enterprise Linux 9.0
Attack profile CVSS 3.1 · 4.5
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Raw vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-3695.md and follow it. Check whether this project is affected by CVE-2021-3695. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
