Message-Authenticator attribute / blastradius mitigation

FreeRADIUS / pam_radius

This is the PAM to RADIUS authentication module. It allows any Linux, OSX or Solaris machine to become a RADIUS client for authentication and password change requests.

GNU General Public License v2.0

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Message-Authenticator attribute / blastradius mitigation #96

Closed todds02 closed 4 months ago

todds02 commented 4 months ago

In reports on the newly announced blastradius vulnerability, a possible mitigation that is suggested is to ensure 'Message-Authenticator' is sent as the first attribute in all request and response messages.

Does pam_radius support this attribute? I don't see any mention of it, and not seeing it in a packet trace. If it does not support the attribute, are there plans to update the library to add it?

alandekok commented 4 months ago

We will be releasing a new version shortly in order to address this issue.

lelandmills commented 4 months ago

Alan, I see you made submissions earlier this week. Should this issue be closed now, or are there more changes planned? Thanks.

alandekok commented 4 months ago

It can be closed. We'll do a new release shortly.

demern commented 3 months ago

Hi, I am also curious if there is any ETA for a new release with the fix? Thanks!

alandekok commented 3 months ago

We hope to do a new release next week

lelandmills commented 3 months ago

Alan, I'd tested the code as submitted last week, and was happy with results. I presumed that the "release" work was mostly release notes and the like. Then, it was found that if multiple radius servers are configured (first in the list is actually non-responsive as intent), then we don't get any response from the good radius server in the second slot - almost like the MessageAuthenticator was incorrect and we were being silently ignored. Doesn't seem I can upload pcap files, but here are screenshots. RadiusFirstServerWorks RadiusSecondServerIgnored Just thought I'd report it before more investigation on my end. Thanks for any enlightenment you might have.

lelandmills commented 3 months ago

Yeah, verified. Each time through the loop of servers, the message_authenticator needs to be set back to 0s before calculating checksum. Something like this works:

    if (request->code == PW_ACCESS_REQUEST) {

memset(conf->message_authenticator, 0, AUTH_VECTOR_LEN); hmac_md5(conf->message_authenticator, (uint8_t ) request, ntohs(request->length), (const uint8_t ) server->secret, strlen(server->secret));

MadhuGowda-Ent commented 3 months ago

Hi Alan, We are using the PAM Authentication and Accounting module. When is the official release expected with fix of of blastradius mitigation (#96).

Thanks, The release 3.0.0 is available.