wpa_supplicant P2P provision discovery processing vulnerability

[Jouni Malinen]

Published: February 25, 2021
Latest version available from: https://w1.fi/security/2021-1/


Vulnerability

A vulnerability was discovered in how wpa_supplicant processes P2P
(Wi-Fi Direct) provision discovery requests. Under a corner case
condition, an invalid Provision Discovery Request frame could end up
reaching a state where the oldest peer entry needs to be removed. With
a suitably constructed invalid frame, this could result in use
(read+write) of freed memory. This can result in an attacker within
radio range of the device running P2P discovery being able to cause
unexpected behavior, including termination of the wpa_supplicant process
and potentially code execution.


Vulnerable versions/configurations

wpa_supplicant v1.0-v2.9 with CONFIG_P2P build option enabled

An attacker (or a system controlled by the attacker) needs to be within
radio range of the vulnerable system to send a set of suitably
constructed management frames that trigger the corner case to be reached
in the management of the P2P peer table.


Possible mitigation steps

- Merge the following commit to wpa_supplicant and rebuild it:

  P2P: Fix a corner case in peer addition based on PD Request
  
  This patch is available from https://w1.fi/security/2021-1/
  
- Update to wpa_supplicant v2.10 or newer, once available

- Disable P2P (control interface command "P2P_SET disabled 1" or
  "p2p_disabled=1" in (each, if multiple interfaces used) wpa_supplicant
  configuration file)

- Disable P2P from the build (remove CONFIG_P2P=y)

-- 
Jouni Malinen                                            PGP id EFC895FA