Red Hat Enterprise Linux 8 update for dovecot

1) NULL pointer dereference

EUVDB-ID: #VU27981

Risk: Medium

CVSSv3.1: 5.9 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2020-10957

CWE-ID: CWE-476 - NULL Pointer Dereference

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 when processing NOOP command. A remote attacker can send a specially crafted NOOP command to submission, submission-login or lmtp service, trigger a NULL pointer dereference and perform a denial of service attack.

PoC command:

``NOOP EE"FY``

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux Server - TUS: 8.2

Red Hat CodeReady Linux Builder for ARM 64: 8.0

Red Hat CodeReady Linux Builder for Power, little endian: 8.0

Red Hat CodeReady Linux Builder for x86_64: 8.0

Red Hat Enterprise Linux for ARM 64: 8

Red Hat Enterprise Linux for Power, little endian: 8

Red Hat Enterprise Linux for IBM z Systems: 8

Red Hat Enterprise Linux for x86_64: 8.0

dovecot (Red Hat package): before 2.3.8-2.el8_2.1

External links

http://access.redhat.com/errata/RHSA-2020:2901

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.