Denial of service in wpa_supplicant

1) Improper input validation

EUVDB-ID: #VU14295

Risk: Low

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

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

CPE2.3

• cpe:2.3:a:jouni_malinen:wpa_supplicant:2.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:jouni_malinen:wpa_supplicant:2.1.0:*:*:*:*:*:*:*
• cpe:2.3:a:jouni_malinen:wpa_supplicant:2.2.0:*:*:*:*:*:*:*

External links

https://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.