Input validation error in dovecot (Alpine package)

1) Input validation error

EUVDB-ID: #VU27984

Risk: Medium

CVSSv3.1: 6.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2020-10967

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input passed via email message. A remote attacker can send a specially crafted email with empty quoted localpart and crash the submission or lmtp service.

PoC:

Send mail with envelope sender or recipient as ``<""@example.org>``.

Mitigation

Install update from vendor's website.

Vulnerable software versions

dovecot (Alpine package): 2.3.2.1-r0 - 2.3.10-r0

External links

http://git.alpinelinux.org/aports/commit/?id=4188e3f4c8c70ca30f481278b85d52799ade266a
http://git.alpinelinux.org/aports/commit/?id=63c2cc277e73718a89df156cafffdaaf5bbad6cc
http://git.alpinelinux.org/aports/commit/?id=e9ada9531d3f3e60456ec07437a2f39f9a196861
http://git.alpinelinux.org/aports/commit/?id=25fe34656b9e14d6e4e67944f178c6687c95c901
http://git.alpinelinux.org/aports/commit/?id=2b1449bb52bbd408ea452e0f29312761f669c517

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. However, proof of concept for this vulnerability is available.