#VU23598 NULL pointer dereference in Dovecot - CVE-2019-19722

Vulnerability identifier: #VU23598

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-19722

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Dovecot
Server applications / Mail servers

Vendor: Dovecot

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error when parsing group emails or empty values in From/To email fields in "src/plugins/push-notification/push-notification-event-message-common.c". A remote attacker can send an email with a group email address or an empty value in From or To fields and crash push notification drivers.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Dovecot: 2.3.9 - 2.3.9.1

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External links
https://github.com/dovecot/core/blob/2.3.9.1/NEWS
https://github.com/dovecot/core/commit/393a8cabf4dad893bf2ec60bf96cfde7a0c58432

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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