What’s Vulnerable › Vulnerabilities

CVE-2020-35679

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-12-24 · updated 2026-06-17
• Weakness: CWE-401

Description

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.

Affected products

• Fedoraproject Fedora: 32, 33
• Opensmtpd: before 6.8.0; 6.8.0, 6.8.0-patch1-rc1 — fixed in 6.8.0

How to fix

Upgrade to a fixed version: Opensmtpd 6.8.0. Check the vendor advisory for mitigations.

References

• https://github.com/openbsd/src/commit/79a034b4aed29e965f45a13409268290c9910043
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LKTFBQCHGMVPR4IZWHQIYAPM5J3LN3J/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TYAYXRV2DM5K4RU7RHCDZSA2UF6VCTRC/
• https://poolp.org/posts/2020-12-24/december-2020-opensmtpd-6.8.0p1-released-fixed-several-bugs-proposed-several-diffs-book-is-on-github/
• https://security.gentoo.org/glsa/202105-12
• https://www.mail-archive.com/misc%40opensmtpd.org/msg05188.html
• https://github.com/openbsd/src/commit/79a034b4aed29e965f45a13409268290c9910043
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5LKTFBQCHGMVPR4IZWHQIYAPM5J3LN3J/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TYAYXRV2DM5K4RU7RHCDZSA2UF6VCTRC/
• https://poolp.org/posts/2020-12-24/december-2020-opensmtpd-6.8.0p1-released-fixed-several-bugs-proposed-several-diffs-book-is-on-github/
• https://security.gentoo.org/glsa/202105-12
• https://www.mail-archive.com/misc%40opensmtpd.org/msg05188.html

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