grub2: Crafted PNG grayscale images may lead to out-of-bounds write in heap
Published Jul 6, 2022
7.5
HIGHCVSS 3.1
EPSS 0.46%
Description
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.
Affected products
- Vendor n/a Product Grub2 Defaultn/a
- Version grub-2.06StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n/a | Grub2 | n/a |
|
Configuration 2
- 36
Configuration 3
- 1.0
- 3.0
- 8.0
- 8.1
- 8.4
- 9.0
- 8.2
- 8.4
- 8.6
- 9.0
- 8.0
- 9.0
- 8.2
- 8.4
- 8.6
- 9.0
- 8.2
- 8.4
- 8.6
- 8.1
- 8.2
- 8.4
- 8.6
- 9.0
- 8.2
- 8.4
- 8.6
Configuration 4
- 4.6
- 4.9
- 4.10
Running on/with
- 8.0
Configuration 5
- n/a
Running on/with
- 8.0
- 9.0
- 8.2
- 8.4
- 8.6
- 9.0
Configuration 6
- n/a
No data.
Red Hat Enterprise Linux 8
grub2-1:2.02-123.el8_6.8
Fixed · RHSA-2022:5095
Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions
grub2-1:2.02-87.el8_1.10
Fixed · RHSA-2022:5098
Red Hat Enterprise Linux 8.2 Extended Update Support
grub2-1:2.02-87.el8_2.10
Fixed · RHSA-2022:5100
Red Hat Enterprise Linux 8.4 Extended Update Support
grub2-1:2.02-99.el8_4.9
Fixed · RHSA-2022:5096
Red Hat Enterprise Linux 9
grub2-1:2.06-27.el9_0.7
Fixed · RHSA-2022:5099
Red Hat Enterprise Linux 7
grub2
Out of support scope
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 8 | grub2-1:2.02-123.el8_6.8 | Fixed | RHSA-2022:5095 |
| Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions | grub2-1:2.02-87.el8_1.10 | Fixed | RHSA-2022:5098 |
| Red Hat Enterprise Linux 8.2 Extended Update Support | grub2-1:2.02-87.el8_2.10 | Fixed | RHSA-2022:5100 |
| Red Hat Enterprise Linux 8.4 Extended Update Support | grub2-1:2.02-99.el8_4.9 | Fixed | RHSA-2022:5096 |
| Red Hat Enterprise Linux 9 | grub2-1:2.06-27.el9_0.7 | Fixed | RHSA-2022:5099 |
| Red Hat Enterprise Linux 7 | grub2 | Out of support scope | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
Due to the nature of the input and how it's processed, a successful attack is considered very complex to be executed, as the same value is written out of bounds three times in a row.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L
1 other source (Red Hat) ▾
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
No CVSS v3.0 score for this CVE.
AV:L/AC:M/Au:N/C:P/I:P/A:P
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (12 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.46% (0.00464) | 37.87th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.44% (0.00440) | 34.84th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.06% (0.00059) | 15.64th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.05% (0.00048) | 19.78th | v3 (v2023.03.01) |
| Jul 10, 2024 | 0.05% (0.00048) | 18.14th | v3 (v2023.03.01) |
| Apr 10, 2024 | 0.05% (0.00048) | 16.11th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.05% (0.00046) | 14.00th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.36% (0.01365) | 71.56th | v2 (v2022.01.01) |
| Oct 1, 2022 | 1.36% (0.01365) | 70.91th | v2 (v2022.01.01) |
| Sep 26, 2022 | 1.00% (0.01005) | 36.60th | v2 (v2022.01.01) |
| Jul 16, 2022 | 1.04% (0.01036) | 40.69th | v2 (v2022.01.01) |
| Jul 7, 2022 | 2.56% (0.02559) | 80.73th | v2 (v2022.01.01) |
References (6)
- https://access.redhat.com/security/cve/CVE-2021-3695 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1991685 x_refsource_MISCIssue TrackingThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2021-3695
- https://security.gentoo.org/glsa/202209-12 vendor-advisoryx_refsource_GENTOOThird Party Advisory
- https://security.netapp.com/advisory/ntap-20220930-0001/ x_refsource_CONFIRMThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2021-3695
| Link | Providers | Tags |
|---|---|---|
| https://access.redhat.com/security/cve/CVE-2021-3695 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1991685 | x_refsource_MISCIssue TrackingThird Party Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2021-3695 | ||
| https://security.gentoo.org/glsa/202209-12 | vendor-advisoryx_refsource_GENTOOThird Party Advisory | |
| https://security.netapp.com/advisory/ntap-20220930-0001/ | x_refsource_CONFIRMThird Party Advisory | |
| https://www.cve.org/CVERecord?id=CVE-2021-3695 |
Change history (0)
No recorded changes yet.