MitM attack in Mutt

1) Cleartext transmission of sensitive information

EUVDB-ID: #VU48662

Risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-28896

CWE-ID: CWE-319 - Cleartext Transmission of Sensitive Information

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to software does not ensure that $ssl_force_tls is processed if an IMAP server's initial server response is invalid. As a result, the connection is not properly closed, and the application continues authentication attempts. A remote attacker with ability to intercept traffic can perform a MitM attack and gain access to victim's credentials.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Mutt: 2.0 - 2.0.1

CPE2.3

• cpe:2.3:a:mutt_org:mutt:2.0:*:*:*:*:*:*:*
• cpe:2.3:a:mutt_org:mutt:2.0.1:*:*:*:*:*:*:*

External links

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

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to visit a specially crafted website or open a file.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.