HIGH
smtpd/lka_filter.c in OpenSMTPD before 6.8.0p1, in certain configurations, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted pattern of client activity, because the filter state machine does not properly maintain the I/O channel between the SMTP engine and the filters layer
Published Dec 24, 2020
7.5
HIGHCVSS 3.1
EPSS 3.65%
Description
smtpd/lka_filter.c in OpenSMTPD before 6.8.0p1, in certain configurations, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted pattern of client activity, because the filter state machine does not properly maintain the I/O channel between the SMTP engine and the filters layer.
Affected products
No data.
Configuration 1
Configuration 2
OR
- 32
- 33
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
7.5 HIGH NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Impact None
Integrity Impact None
Availability Impact High
No CVSS v3.0 score for this CVE.
5.0 MEDIUM NVD
AV:N/AC:L/Au:N/C:N/I:N/A:P
Access Vector Network
Access Complexity Low
Authentication None
Confidentiality Impact None
Integrity Impact None
Availability Impact Partial
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
3.65% 0.03652
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 2, 2026.
EPSS probability 0.03652
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 (25 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 3.65% (0.03652) | 89.25th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.58% (0.03578) | 87.86th | v5 (v2026.06.15) |
| May 29, 2026 | 5.80% (0.05798) | 90.64th | v4 (v2025.03.14) |
| Mar 30, 2025 | 4.25% (0.04249) | 87.73th | v4 (v2025.03.14) |
| Mar 29, 2025 | 50.04% (0.50040) | 96.82th | v4 (v2025.03.14) |
| Mar 24, 2025 | 4.25% (0.04249) | 87.73th | v4 (v2025.03.14) |
| Mar 23, 2025 | 29.96% (0.29962) | 96.10th | v4 (v2025.03.14) |
| Mar 17, 2025 | 4.25% (0.04249) | 88.05th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.87% (0.00868) | 83.09th | v3 (v2023.03.01) |
| May 3, 2024 | 0.76% (0.00756) | 80.94th | v3 (v2023.03.01) |
| Nov 8, 2023 | 0.76% (0.00756) | 78.88th | v3 (v2023.03.01) |
| Sep 9, 2023 | 1.64% (0.01644) | 86.02th | v3 (v2023.03.01) |
| Jul 31, 2023 | 1.45% (0.01447) | 84.90th | v3 (v2023.03.01) |
| Jul 19, 2023 | 1.28% (0.01281) | 83.92th | v3 (v2023.03.01) |
| Jul 5, 2023 | 1.27% (0.01273) | 83.77th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.90% (0.00901) | 80.25th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.32% (0.01319) | 71.27th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.32% (0.01319) | 71.23th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.32% (0.01319) | 69.22th | v2 (v2022.01.01) |
| Feb 4, 2022 | 8.93% (0.08934) | 82.99th | v2 (v2022.01.01) |
| Feb 3, 2022 | 9.41% (0.09409) | 86.81th | v1 |
| Jan 6, 2022 | 9.41% (0.09409) | 86.65th | v1 |
| Sep 1, 2021 | 2.26% (0.02262) | 77.65th | v1 |
| May 27, 2021 | 2.26% (0.02262) | 0.00th | v1 |
| Apr 14, 2021 | 1.94% (0.01943) | 0.00th | v1 |
Weaknesses (1)
References (6)
- https://github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1 x_refsource_MISCPatchThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LKTFBQCHGMVPR4IZWHQIYAPM5J3LN3J/ vendor-advisoryx_refsource_FEDORA
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TYAYXRV2DM5K4RU7RHCDZSA2UF6VCTRC/ vendor-advisoryx_refsource_FEDORA
- https://poolp.org/posts/2020-12-24/december-2020-opensmtpd-6.8.0p1-released-fixed-several-bugs-proposed-several-diffs-book-is-on-github/ x_refsource_MISCThird Party Advisory
- https://security.gentoo.org/glsa/202105-12 vendor-advisoryx_refsource_GENTOOThird Party Advisory
- https://www.mail-archive.com/misc%40opensmtpd.org/msg05188.html x_refsource_MISC
| Link | Providers | Tags |
|---|---|---|
| https://github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1 | x_refsource_MISCPatchThird Party Advisory | |
| https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LKTFBQCHGMVPR4IZWHQIYAPM5J3LN3J/ | vendor-advisoryx_refsource_FEDORA | |
| https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TYAYXRV2DM5K4RU7RHCDZSA2UF6VCTRC/ | vendor-advisoryx_refsource_FEDORA | |
| https://poolp.org/posts/2020-12-24/december-2020-opensmtpd-6.8.0p1-released-fixed-several-bugs-proposed-several-diffs-book-is-on-github/ | x_refsource_MISCThird Party Advisory | |
| https://security.gentoo.org/glsa/202105-12 | vendor-advisoryx_refsource_GENTOOThird Party Advisory | |
| https://www.mail-archive.com/misc%40opensmtpd.org/msg05188.html | x_refsource_MISC |
Change history (0)
No recorded changes yet.
Sources
CVE.org / MITRE
Status PUBLISHED
Assigner mitre
Published Dec 24, 2020
Updated Aug 4, 2024
Reserved Dec 24, 2020
Link CVE-2020-35680
CISA Vulnrichment
Updated n/a