CVE catalog

CVE-2020-7957

dovecot: CVE-2020-7957

Severity: Medium · CVSS 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Published: Feb 12, 2020, 5:15:12 PM UTC
Source: [NVD] · [CVE record]
EPSS: 1.88% · Oct 25, 2026

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.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	dovecot	sid	`1:2.4.5+dfsg1-4`	not affected
Debian	dovecot	forky	`1:2.4.5+dfsg1-4`	not affected
Debian	dovecot	trixie	`1:2.4.1+dfsg1-6+deb13u6`	not affected
Debian	dovecot	trixie-security	`1:2.4.1+dfsg1-6+deb13u7`	not affected
Debian	dovecot	bookworm	`1:2.3.19.1+dfsg1-2.1+deb12u6`	not affected
Debian	dovecot	bookworm-security	`1:2.3.19.1+dfsg1-2.1+deb12u6`	not affected
Alpine	dovecot	3.10	`2.3.10.1-r0`	fixed
Alpine	dovecot	3.11	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.12	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.13	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.14	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.15	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.16	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.17	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.18	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.19	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.20	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.21	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.22	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.23	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.24	`2.3.9.3-r0`	fixed
Alpine	dovecot	3.8	`2.3.10.1-r0`	fixed
Alpine	dovecot	3.9	`2.3.10.1-r0`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	dovecot	source	sid	`Not affected`	unimportant	Not reported	Not reported
Debian	dovecot	source	forky	`Not affected`	unimportant	Not reported	Not reported
Debian	dovecot	source	trixie	`Not affected`	unimportant	Not reported	Not reported
Debian	dovecot	source	bookworm	`Not affected`	unimportant	Not reported	Not reported
Alpine	dovecot	apk	3.10	`2.3.10.1-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.11	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.12	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.13	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.14	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.15	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.16	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.17	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.18	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.19	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.20	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.21	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.22	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.23	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.24	`2.3.9.3-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.8	`2.3.10.1-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported
Alpine	dovecot	apk	3.9	`2.3.10.1-r0`	Not reported	ALPINE-CVE-2020-7957	Not reported

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

[dovecot-auth-lua]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-core]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-dev]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-gssapi]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-imapd]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-ldap]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-lmtpd]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-lucene]Unknown
Source package: [dovecot]
Details (4)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-managesieved]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-mysql]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-pgsql]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-pop3d]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-sieve]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-solr]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-sqlite]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
[dovecot-submissiond]Unknown
Source package: [dovecot]
Details (6)
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · amd64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.21.1+dfsg1-1~bpo12+1 · arm64 · bookworm-backports
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · amd64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm
- 1:2.3.19.1+dfsg1-2.1+deb12u6 · arm64 · bookworm-security
  Not affected
  dsa · dovecot · debian · bookworm

Observed: Oct 23, 2026, 5:53:17 PM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [SUSE security advisories and VEX]