[krbdev.mit.edu #8018] git commit

[Tom Yu via RT]

Return only new keys in randkey [CVE-2014-5351]

In kadmind's randkey operation, if a client specifies the keepold
flag, do not include the preserved old keys in the response.

CVE-2014-5351:

An authenticated remote attacker can retrieve the current keys for a
service principal when generating a new set of keys for that
principal.  The attacker needs to be authenticated as a user who has
the elevated privilege for randomizing the keys of other principals.

Normally, when a Kerberos administrator randomizes the keys of a
service principal, kadmind returns only the new keys.  This prevents
an administrator who lacks legitimate privileged access to a service
from forging tickets to authenticate to that service.  If the
"keepold" flag to the kadmin randkey RPC operation is true, kadmind
retains the old keys in the KDC database as intended, but also
unexpectedly returns the old keys to the client, which exposes the
service to ticket forgery attacks from the administrator.

A mitigating factor is that legitimate clients of the affected service
will start failing to authenticate to the service once they begin to
receive service tickets encrypted in the new keys.  The affected
service will be unable to decrypt the newly issued tickets, possibly
alerting the legitimate administrator of the affected service.

CVSSv2: AV:N/AC:H/Au:S/C:P/I:N/A:N/E:POC/RL:OF/RC:C

[tlyu at mit.edu: CVE description and CVSS score]

(cherry picked from commit af0ed4df4dfae762ab5fb605f5a0c8f59cb4f6ca)

https://github.com/krb5/krb5/commit/3bf9e33f9d66c0eef486cbd83f9e4f13a74d12c3
Author: Greg Hudson <ghudson at mit.edu>
Committer: Tom Yu <tlyu at mit.edu>
Commit: 3bf9e33f9d66c0eef486cbd83f9e4f13a74d12c3
Branch: krb5-1.13
 src/lib/kadm5/srv/svr_principal.c |   21 ++++++++++++++++++---
 1 files changed, 18 insertions(+), 3 deletions(-)