The following flaw was reported in hostapd:

A vulnerability was found in EAP-pwd server and peer implementation used in hostapd and wpa_supplicant, respectively. When an incoming EAP-pwd message is fragmented, the remaining reassembly buffer length was not checked for the last fragment (but was checked for other fragments). This allowed a suitably constructed last fragment frame to try to add extra data that would go beyond the buffer. The length validation code in wpabuf_put_data() prevents an actual buffer write overflow from occurring, but this results in process termination.

For hostapd used with an internal EAP server and EAP-pwd enabled in the runtime configuration, this could allow a denial of service attack by an attacker within radio range of the AP device.

For hostapd used as a RADIUS server with EAP-pwd enabled in the runtime configuration, this could allow a denial of service attack by an attacker within radio range of any AP device that is authorized to use the RADIUS server.

Vulnerable versions/configurations:

hostapd v1.0-v2.5 with CONFIG_EAP_PWD=y in the build configuration (hostapd/.config) and EAP-pwd authentication server enabled in runtime configuration.

Possible workarounds:

- Remove CONFIG_EAP_PWD=y from build configuration

- Disable EAP-pwd in runtime configuration

The related issue in wpa_supplicant is filed under CVE-2015-5315.

External References:

http://w1.fi/security/2015-7/