What’s Vulnerable › Vulnerabilities
CVE-2020-28896
- Severity: medium (CVSS 5.3 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 2.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2020-11-23 · updated 2026-06-17
- Weakness: CWE-287
Description
Mutt before 2.0.2 and NeoMutt before 2020-11-20 did not ensure that $ssl_force_tls was processed if an IMAP server's initial server response was invalid. The connection was not properly closed, and the code could continue attempting to authenticate. This could result in authentication credentials being exposed on an unencrypted connection, or to a machine-in-the-middle.
Affected products
- Debian Linux: 9.0
- mutt: before 2.0.2 — fixed in 2.0.2
- Neomutt: before 2020-11-20 — fixed in 2020-11-20
How to fix
Upgrade to a fixed version: mutt 2.0.2; Neomutt 2020-11-20. Check the vendor advisory for mitigations.
References
- https://github.com/neomutt/neomutt/commit/9c36717a3e2af1f2c1b7242035455ec8112b4b06
- https://github.com/neomutt/neomutt/releases/tag/20201120
- https://gitlab.com/muttmua/mutt/-/commit/04b06aaa3e0cc0022b9b01dbca2863756ebbf59a
- https://gitlab.com/muttmua/mutt/-/commit/d92689088dfe80a290ec836e292376e2d9984f8f
- https://lists.debian.org/debian-lts-announce/2020/11/msg00048.html
- https://security.gentoo.org/glsa/202101-32
- https://github.com/neomutt/neomutt/commit/9c36717a3e2af1f2c1b7242035455ec8112b4b06
- https://github.com/neomutt/neomutt/releases/tag/20201120
- https://gitlab.com/muttmua/mutt/-/commit/04b06aaa3e0cc0022b9b01dbca2863756ebbf59a
- https://gitlab.com/muttmua/mutt/-/commit/d92689088dfe80a290ec836e292376e2d9984f8f
- https://lists.debian.org/debian-lts-announce/2020/11/msg00048.html
- https://security.gentoo.org/glsa/202101-32
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