kernel: improper input validation in ppp_cp_parse_cr function leads to memory corruption and read overflow
Published Oct 6, 2020
7.2
HIGHCVSS 3.1
EPSS 3.29%
Description
A flaw was found in the HDLC_PPP module of the Linux kernel in versions before 5.9-rc7. Memory corruption and a read overflow is caused by improper input validation in the ppp_cp_parse_cr function which can cause the system to crash or cause a denial of service. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Affected products
- Vendor n/a Product Kernel Defaultn/a
- Version Linux kernel versions before 5.9-rc7StatusaffectedConstraints-
- 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 | Kernel | n/a |
|
Configuration 1
- ≥ 2.6.29 · < 4.4.238
- ≥ 4.5 · < 4.9.238
- ≥ 4.10 · < 4.14.200
- ≥ 4.15 · < 4.19.148
- ≥ 4.20 · < 5.4.68
- ≥ 5.5 · < 5.8.12
- 5.9.0
- 5.9.0
- 5.9.0
- 5.9.0
- 5.9.0
- 5.9.0
Configuration 2
- 7.0
- 8.0
Configuration 4
- 9.0
- 10.0
Configuration 6
- n/a
Configuration 7
- v8
- v8
- v8
- v8
- v8
- v8
No data.
Red Hat Enterprise Linux 7
kernel-0:3.10.0-1160.11.1.el7
Fixed · RHSA-2020:5437
Red Hat Enterprise Linux 7
kernel-rt-0:3.10.0-1160.11.1.rt56.1145.el7
Fixed · RHSA-2020:5441
Red Hat Enterprise Linux 8
kernel-0:4.18.0-305.el8
Fixed · RHSA-2021:1578
Red Hat Enterprise Linux 8
kernel-rt-0:4.18.0-305.rt7.72.el8
Fixed · RHSA-2021:1739
Red Hat Enterprise Linux 5
kernel
Not affected
Red Hat Enterprise Linux 6
kernel
Out of support scope
Red Hat Enterprise Linux 7
kernel-alt
Will not fix
Red Hat Enterprise MRG 2
kernel-rt
Out of support scope
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 | kernel-0:3.10.0-1160.11.1.el7 | Fixed | RHSA-2020:5437 |
| Red Hat Enterprise Linux 7 | kernel-rt-0:3.10.0-1160.11.1.rt56.1145.el7 | Fixed | RHSA-2020:5441 |
| Red Hat Enterprise Linux 8 | kernel-0:4.18.0-305.el8 | Fixed | RHSA-2021:1578 |
| Red Hat Enterprise Linux 8 | kernel-rt-0:4.18.0-305.rt7.72.el8 | Fixed | RHSA-2021:1739 |
| Red Hat Enterprise Linux 5 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | n/a |
| Red Hat Enterprise Linux 7 | kernel-alt | Will not fix | n/a |
| Red Hat Enterprise MRG 2 | kernel-rt | Out of support scope | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This flaw is rated as a having Moderate impact, because the bug can be triggered only if PPP protocol enabled.
Red Hat mitigation
To mitigate this issue, prevent modules hdlc_ppp, syncppp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
No CVSS v3.0 score for this CVE.
AV:N/AC:M/Au:S/C:P/I:P/A:C
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
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (16 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 3.29% (0.03292) | 88.08th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.25% (0.03252) | 86.68th | v5 (v2026.06.15) |
| Nov 21, 2025 | 0.39% (0.00394) | 59.61th | v4 (v2025.03.14) |
| Nov 18, 2025 | 1.49% (0.01493) | 79.44th | v4 (v2025.03.14) |
| Mar 17, 2025 | 0.49% (0.00491) | 63.53th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.11% (0.00114) | 46.69th | v3 (v2023.03.01) |
| Jul 8, 2023 | 0.08% (0.00084) | 34.52th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.13% (0.00129) | 45.90th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.28% (0.01282) | 68.34th | v2 (v2022.01.01) |
| Feb 22, 2023 | 1.28% (0.01282) | 68.05th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.28% (0.01282) | 65.91th | v2 (v2022.01.01) |
| Feb 4, 2022 | 16.20% (0.16200) | 92.74th | v2 (v2022.01.01) |
| Feb 3, 2022 | 8.80% (0.08796) | 86.41th | v1 |
| Jan 6, 2022 | 8.80% (0.08796) | 86.25th | v1 |
| Sep 1, 2021 | 2.10% (0.02104) | 77.33th | v1 |
| Apr 14, 2021 | 2.10% (0.02104) | 0.00th | v1 |
References (13)
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00021.html vendor-advisoryThird Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00042.html vendor-advisoryMailing ListThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2020-25643 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1879981 Issue TrackingPatchThird Party Advisory
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=66d42ed8b25b64eb63111a2b8582c5afc8bf1105 Mailing ListPatchThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/10/msg00028.html mailing-listMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html mailing-listMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html mailing-listMailing ListThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2020-25643
- https://security.netapp.com/advisory/ntap-20201103-0002/ Third Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2020-25643
- https://www.debian.org/security/2020/dsa-4774 vendor-advisoryThird Party Advisory
- https://www.starwindsoftware.com/security/sw-20210325-0002/ Third Party Advisory
Change history (0)
No recorded changes yet.