Bug#927463: wpa: EAP-pwd message reassembly issue with unexpected fragment

2019-04-25 Thread Andrej Shadura
Hi,

On Sat, 20 Apr 2019 at 08:15, Salvatore Bonaccorso  wrote:
> Hi
>
> From [1]
>
> > EAP-pwd message reassembly issue with unexpected fragment
> >
> > Published: April 18, 2019
> > Latest version available from: https://w1.fi/security/2019-5/

Thanks for filing the bug. I was aware of this issue but since I was
about to leave for a holiday, I did nothing on that front :) I will
address it tomorrow.

-- 
Cheers,
  Andrej



Bug#927463: wpa: EAP-pwd message reassembly issue with unexpected fragment

2019-04-20 Thread Salvatore Bonaccorso
Source: wpa
Version: 2:2.7+git20190128+0c1e29f-4
Severity: important
Tags: patch security upstream

Hi

>From [1]

> EAP-pwd message reassembly issue with unexpected fragment
> 
> Published: April 18, 2019
> Latest version available from: https://w1.fi/security/2019-5/
> 
> Vulnerability
> 
> EAP-pwd implementation in hostapd (EAP server) and wpa_supplicant (EAP
> peer) was discovered not to validate fragmentation reassembly state
> properly for a case where an unexpected fragment could be received. This
> could result in process termination due to NULL pointer dereference.
> 
> An attacker in radio range of a station device with wpa_supplicant
> network profile enabling use of EAP-pwd could cause the wpa_supplicant
> process to terminate by constructing unexpected sequence of EAP
> messages. An attacker in radio range of an access point that points to
> hostapd as an authentication server with EAP-pwd user enabled in runtime
> configuration (or in non-WLAN uses of EAP authentication as long as the
> attacker can send EAP-pwd messages to the server) could cause the
> hostapd process to terminate by constructing unexpected sequence of EAP
> messages.
> 
> 
> Vulnerable versions/configurations
> 
> All hostapd and wpa_supplicant versions with EAP-pwd support
> (CONFIG_EAP_PWD=y in the build configuration and EAP-pwd being enabled
> in the runtime configuration) are vulnerable against the process
> termination (denial of service) attack.
> 
> 
> Possible mitigation steps
> 
> - Merge the following commits to wpa_supplicant/hostapd and rebuild:
> 
>   EAP-pwd peer: Fix reassembly buffer handling
>   EAP-pwd server: Fix reassembly buffer handling
> 
>   These patches are available from https://w1.fi/security/2019-5/
> 
> - Update to wpa_supplicant/hostapd v2.8 or newer, once available

 [1] 
https://w1.fi/security/2019-5/eap-pwd-message-reassembly-issue-with-unexpected-fragment.txt

Not a CVE assigned AFAIK (yet).

Regards,
Salvatore