lib-smtp in submission-login and lmtp in Dovecot 2.3.9 before 2.3.9.3 mishandles truncated UTF-8 data in command parameters, as demonstrated by the unauthenticated triggering of a submission-login infinite loop.

According to the versions of the dovecot packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - In Dovecot before 2.3.10.1, unauthenticated sending of     malformed parameters to a NOOP command causes a NULL     Pointer Dereference and crash in submission-login,     submission, or lmtp.(CVE-2020-10957)

  - In Dovecot before 2.3.10.1, remote unauthenticated     attackers can crash the lmtp or submission process by     sending mail with an empty localpart.(CVE-2020-10967)

  - In Dovecot before 2.3.10.1, a crafted SMTP/LMTP message     triggers an unauthenticated use-after-free bug in     submission-login, submission, or lmtp, and can lead to     a crash under circumstances involving many newlines     after a command.(CVE-2020-10958)

  - lib-smtp in submission-login and lmtp in Dovecot 2.3.9     before 2.3.9.3 mishandles truncated UTF-8 data in     command parameters, as demonstrated by the     unauthenticated triggering of a submission-login     infinite loop.(CVE-2020-7046)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

- dovecot updated to 2.3.9.3

  - fixes CVE-2020-7046: Truncated UTF-8 can be used to DoS     submission-login and lmtp processes.

  - fixes CVE-2020-7957: Specially crafted mail can crash     snippet generation.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Aki Tuomi reports :

lib-smtp doesn't handle truncated command parameters properly, resulting in infinite loop taking 100% CPU for the process. This happens for LMTP (where it doesn't matter so much) and also for submission-login where unauthenticated users can trigger it. 

Aki also reports :

Snippet generation crashes if :

message is large enough that message-parser returns multiple body blocks The first block(s) don't contain the full snippet (e.g. full of whitespace) input ends with '>'

ID	Name	Product	Family	Severity
139946	EulerOS 2.0 SP8 : dovecot (EulerOS-SA-2020-1843)	Nessus	Huawei Local Security Checks	high
133818	Fedora 31 : 1:dovecot (2020-10a58fda28)	Nessus	Fedora Local Security Checks	high
133817	Fedora 30 : 1:dovecot (2020-0e6a67af5a)	Nessus	Fedora Local Security Checks	high
133661	FreeBSD : dovecot -- multiple vulnerabilities (74db0d02-b140-4c32-aac6-1f1e81e1ad30)	Nessus	FreeBSD Local Security Checks	medium

Detections

Analytics

CVE-2020-7046

high

Tenable Plugins

high

high

high

medium