#VU45671 Infinite loop in Dovecot - CVE-2020-12100

Vulnerability identifier: #VU45671

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-2020-12100

CWE-ID: CWE-835

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 infinite loop in submission, lmtp, and lda when processing e-mail message with deeply nested MIME parts. A remote attacker can send a specially crafted email to consume all available system resources and cause denial of service conditions.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Dovecot: 2.3.0 - 2.3.11.2

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External links
https://dovecot.org/pipermail/dovecot-news/2020-August/000441.html

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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.