CVE-2021-3695
Publication date 6 July 2022
Last updated 24 July 2024
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| grub2 | 24.10 oracular |
Not affected
|
| 24.04 LTS noble |
Not affected
|
|
| 22.04 LTS jammy |
Not affected
|
|
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial |
Not affected
|
|
| 14.04 LTS trusty |
Not affected
|
|
| grub2-signed | 24.10 oracular |
Not affected
|
| 24.04 LTS noble |
Not affected
|
|
| 22.04 LTS jammy |
Fixed 1.187.3~22.04.1
|
|
| 20.04 LTS focal |
Fixed 1.187.3~20.04.1
|
|
| 18.04 LTS bionic |
Fixed 1.187.3~18.04.1
|
|
| 16.04 LTS xenial |
Vulnerable
|
|
| 14.04 LTS trusty |
Vulnerable
|
|
| grub2-unsigned | 24.10 oracular |
Not affected
|
| 24.04 LTS noble |
Not affected
|
|
| 22.04 LTS jammy |
Fixed 2.06-2ubuntu14.1
|
|
| 20.04 LTS focal |
Fixed 2.06-2ubuntu14.1
|
|
| 18.04 LTS bionic |
Fixed 2.06-2ubuntu14.1
|
|
| 16.04 LTS xenial |
Vulnerable
|
|
| 14.04 LTS trusty | Not in release |
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
4.5 · Medium
|
| Attack vector | Local |
| Attack complexity | High |
| Privileges required | Low |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | Low |
| Integrity impact | Low |
| Availability impact | Low |
| Vector | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L |
References
Related Ubuntu Security Notices (USN)
- USN-6355-1
- GRUB2 vulnerabilities
- 8 September 2023