What’s Vulnerable › Vulnerabilities
CVE-2020-7957
- Severity: medium (CVSS 5.3 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.9% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2020-02-12 · updated 2026-06-17
- Weakness: CWE-20
Description
The IMAP and LMTP components in Dovecot 2.3.9 before 2.3.9.3 mishandle snippet generation when many characters must be read to compute the snippet and a trailing > character exists. This causes a denial of service in which the recipient cannot read all of their messages.
Affected products
- dovecot: from 2.3.9 before 2.3.9.3 — fixed in 2.3.9.3
- Fedoraproject Fedora: 30, 31
How to fix
Upgrade to a fixed version: dovecot 2.3.9.3. Check the vendor advisory for mitigations.
References
- http://www.openwall.com/lists/oss-security/2020/02/12/2
- https://dovecot.org/pipermail/dovecot-news/2020-February/000430.html
- https://dovecot.org/security
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6XYT55WH372BJOXCJRKBDIFGBMPVOIDT/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NJXHOUT3FH2DJNMACSX4GHPP4MUV4UKA/
- http://www.openwall.com/lists/oss-security/2020/02/12/2
- https://dovecot.org/pipermail/dovecot-news/2020-February/000430.html
- https://dovecot.org/security
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6XYT55WH372BJOXCJRKBDIFGBMPVOIDT/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NJXHOUT3FH2DJNMACSX4GHPP4MUV4UKA/
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