#VU18399 NULL pointer dereference in Dovecot - CVE-2019-11494

Vulnerability identifier: #VU18399

Vulnerability risk: Medium

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

CVE-ID: CVE-2019-11494

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 within Submission-login when processing authentication. A remote attacker can unexpectedly abort the authentication process by disconnecting from the server during authentication and cause the software to crash.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Dovecot: 2.3.0 - 2.3.5.2

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External links
https://dovecot.org/doc/NEWS-2.3

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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