Red Hat Enterprise Linux 7 update for avahi

1) Input validation error

EUVDB-ID: #VU17349

Risk: Low

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-6519

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to avahi-daemon inadvertently responds to IPv6 unicast queries with source addresses that are not on-link. A remote attacker can submit specially crafted port-5353 UDP packet to trigger traffic amplification and cause the service to crash.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux for Power, little endian: 7

Red Hat Enterprise Linux for Power, big endian: 7

Red Hat Enterprise Linux for IBM z Systems: 7

Red Hat Enterprise Linux for Scientific Computing: 7

Red Hat Enterprise Linux Desktop: 7

Red Hat Enterprise Linux Workstation: 7

Red Hat Enterprise Linux Server: 7

avahi (Red Hat package): before 0.6.31-20.el7

External links

http://access.redhat.com/errata/RHSA-2020:1176

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.