#VU23612 Expected behavior violation in hostapd - CVE-2019-5061

Vulnerability identifier: #VU23612

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:A/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-2019-5061

CWE-ID: CWE-440

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
hostapd
Server applications / Remote access servers, VPN

Vendor: Jouni Malinen

Description

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

The vulnerability exists due to an Authentication and AssociationRequest packet is sent before the station has successfully authenticated. A remote attacker on the local network can iterate through a large set of unique MAC addresses to trigger DoS attacks within the upstream network infrastructure.

This can lead to different denial of service scenarios, either by causing CAM table attacks, or by leading to traffic flapping if faking already existing clients in other nearby Aps of the same wireless infrastructure.

Note: This vulnerability affects hostapd Ubiquiti AP-AC-Pro firmware 4.0.10.9653

Mitigation
Install updates from vendor's website.

Vulnerable software versions

hostapd: 2.6

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External links
https://talosintelligence.com/vulnerability_reports/TALOS-2019-0849

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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 local network (LAN).

Is there known malware, which exploits this vulnerability?

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