CVE-2019-10691 Denial of service in n/a

High 7.5 Published 24 Apr 2019 Updated 4 Aug 2024

Attackers can crash the Dovecot authentication service by sending invalid UTF-8 sequences as usernames, causing a denial of service.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2019-10691?

CVE-2019-10691 is a high-severity denial of service vulnerability in Dovecot Dovecot, published on 24 Apr 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The JSON encoder in Dovecot before 2.3.5.2 allows attackers to repeatedly crash the authentication service by attempting to authenticate with an invalid UTF-8 sequence as the username.

Which versions are affected by CVE-2019-10691?

It affects 2 products.

Linux distribution packages (2)

`dovecot23` SUSE:Linux Enterprise Module for Server Applications 15	All versions	`2.3.3-4.13.1`
`dovecot23` openSUSE:Leap 15.0	All versions	`2.3.3-lp150.11.1`

Products include Dovecot Dovecot, Opensuse Leap.

How do I fix CVE-2019-10691?

Upgrade to a fixed version.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2019-10691 being exploited?

There is no known exploitation of CVE-2019-10691 in the wild and no public exploit code.

All Dovecot Dovecot vulnerabilities

Sources

Also known as ALPINE-CVE-2019-10691, DEBIAN-CVE-2019-10691, GHSA-7m29-wr8r-5c2m, SUSE-SU-2019:0997-1, openSUSE-SU-2019:1312-1.