Denial of service in wpa_supplicant

1) Improper input validation

EUVDB-ID: #VU14295

Risk: Low

CVSSv3.1: 6.9 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:U/RC:C]

CVE-ID: CVE-2018-14526

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The vulnerability exists on the systems where WPA2/RSN style of EAPOL-Key construction is used with TKIP negotiated as the pairwise cipher due to an error when processing malicious input. A remote attacker can send specially crafted unauthenticated EAPOL-Key frame data to modify the Group Transient Key (GTK) and prevent the target system from accepting group-addressed frames.

Mitigation

The vendor offers possible mitigation steps:

- Remove TKIP as an allowed pairwise cipher in RSN/WPA2 networks. This
can be done also on the AP side.

- Merge the following commits to wpa_supplicant and rebuild:

WPA: Ignore unauthenticated encrypted EAPOL-Key data

- Update to wpa_supplicant v2.7 or newer, once available.

Vulnerable software versions

wpa_supplicant: 2.0.0 - 2.6

External links

http://w1.fi/security/2018-1/unauthenticated-eapol-key-decryption.txt

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.