CVE-2020-35679

smtpd/table.c in OpenSMTPD before 6.8.0p1 lacks a certain regfree, which might allow attackers to trigger a "very significant" memory leak via messages to an instance that performs many regex lookups.

Published: 2020-12-24 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-35679 is rated Moderate Risk (60.5/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.37%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-35679

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-29 1.70% 2.37% +0.67%
2 2025-11-21 2.37% 1.70% -0.67%
3 2025-11-18 2.37%

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-35679

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-35679

OS Trackers for CVE-2020-35679

vendor priority summary link
alpine high CVE-2020-35679: 1 source package rows (opensmtpd); 6 state rows across 6 repos (3.10-main, 3.11-main, 3.12-main, 3.22-community, edge-community, edge-main); fixed 2, open 4. https://security.alpinelinux.org/vuln/CVE-2020-35679
debian not yet assigned CVE-2020-35679 not yet assigned priority: Debian including 1 source packages (opensmtpd), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-35679
gentoo low CVE-2020-35679: 1 GLSA(s) (202105-12), 1 atom(s) (mail-mta/opensmtpd); latest impact low. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-35679
ubuntu medium CVE-2020-35679 medium priority: Ubuntu including 1 source packages (opensmtpd), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 8, needed 4, needs-triage 2, not-affected 2. https://ubuntu.com/security/CVE-2020-35679

Affected software / configurations for CVE-2020-35679

Vendor Product Version Raw CPE
opensmtpd opensmtpd < 6.8.0 cpe:2.3:a:opensmtpd:opensmtpd:*:*:*:*:*:*:*:*
opensmtpd opensmtpd 6.8.0 cpe:2.3:a:opensmtpd:opensmtpd:6.8.0:-:*:*:*:*:*:*
opensmtpd opensmtpd 6.8.0 cpe:2.3:a:opensmtpd:opensmtpd:6.8.0:patch1-rc1:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*

References for CVE-2020-35679

cvelogic Threat Intelligence