| From: | ghudson@mit.edu |
| Subject: | git commit |
Fix double-free in KDC TGS processing
When issuing a ticket for a TGS renew or validate request, copy only
the server field from the outer part of the header ticket to the new
ticket. Copying the whole structure causes the enc_part pointer to be
aliased to the header ticket until krb5_encrypt_tkt_part() is called,
resulting in a double-free if handle_authdata() fails.
[ghudson@mit.edu: changed the fix to avoid aliasing enc_part rather
than check for aliasing before freeing; rewrote commit message]
CVE-2023-39975:
In MIT krb5 release 1.21, an authenticated attacker can cause a KDC to
free the same pointer twice if it can induce a failure in
authorization data handling.
https://github.com/krb5/krb5/commit/88a1701b423c13991a8064feeb26952d3641d840
Author: Andreas Schneider <asn@samba.org>
Committer: Greg Hudson <ghudson@mit.edu>
Commit: 88a1701b423c13991a8064feeb26952d3641d840
Branch: master
src/kdc/do_tgs_req.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)