Prevent KDC unset status assertion failures Assign status values if S4U2Self padata fails to decode, if an S4U2Proxy request uses invalid KDC options, or if an S4U2Proxy request uses an evidence ticket which does not match the canonicalized request server principal name. Reported by Samuel Cabrero. If a status value is not assigned during KDC processing, default to "UNKNOWN_REASON" rather than failing an assertion. This change will prevent future denial of service bugs due to similar mistakes, and will allow us to omit assigning status values for unlikely errors such as small memory allocation failures. CVE-2017-11368: In MIT krb5 1.7 and later, an authenticated attacker can cause an assertion failure in krb5kdc by sending an invalid S4U2Self or S4U2Proxy request. CVSSv3 Vector: AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:H/RL:O/RC:C (cherry picked from commit ffb35baac6981f9e8914f8f3bffd37f284b85970) https://github.com/krb5/krb5/commit/f1190a43fb6de5b70a11cd6ec97978e05b6083f1 Author: Greg Hudson Commit: f1190a43fb6de5b70a11cd6ec97978e05b6083f1 Branch: krb5-1.14 src/kdc/do_as_req.c | 4 ++-- src/kdc/do_tgs_req.c | 3 ++- src/kdc/kdc_util.c | 10 ++++++++-- 3 files changed, 12 insertions(+), 5 deletions(-)