A flawed logical condition allows a malicious actor to remotely
trigger a NULL pointer dereference using a crafted negTokenInit
token.
Upstream notes:
Reported to Heimdal by Michał Kępień <michal@isc.org>.
From the report:
Acknowledgement
---------------
This flaw was found while working on addressing ZDI-CAN-12302: ISC BIND
TKEY Query Heap-based Buffer Overflow Remote Code Execution
Vulnerability, which was reported to ISC by Trend Micro's Zero Day
Security: CVE-2022-3116
Obtained from: upstream 7a19658c1
(cherry picked from commit fc773115fa)
The following issues are patched:
- CVE-2022-42898 PAC parse integer overflows
- CVE-2022-3437 Overflows and non-constant time leaks in DES{,3} and arcfour
- CVE-2021-44758 NULL dereference DoS in SPNEGO acceptors
- CVE-2022-44640 Heimdal KDC: invalid free in ASN.1 codec
Note that CVE-2022-44640 is a severe vulnerability, possibly a 10.0
on the Common Vulnerability Scoring System (CVSS) v3, as we believe
it should be possible to get an RCE on a KDC, which means that
credentials can be compromised that can be used to impersonate
anyone in a realm or forest of realms.
Heimdal's ASN.1 compiler generates code that allows specially
crafted DER encodings of CHOICEs to invoke the wrong free function
on the decoded structure upon decode error. This is known to impact
the Heimdal KDC, leading to an invalid free() of an address partly
or wholly under the control of the attacker, in turn leading to a
potential remote code execution (RCE) vulnerability.
This error affects the DER codec for all extensible CHOICE types
used in Heimdal, though not all cases will be exploitable. We have
not completed a thorough analysis of all the Heimdal components
affected, thus the Kerberos client, the X.509 library, and other
parts, may be affected as well.
This bug has been in Heimdal's ASN.1 compiler since 2005, but it may
only affect Heimdal 1.6 and up. It was first reported by Douglas
Bagnall, though it had been found independently by the Heimdal
maintainers via fuzzing a few weeks earlier.
While no zero-day exploit is known, such an exploit will likely be
available soon after public disclosure.
- CVE-2019-14870: Validate client attributes in protocol-transition
- CVE-2019-14870: Apply forwardable policy in protocol-transition
- CVE-2019-14870: Always lookup impersonate client in DB
Sponsored by: so (philip)
Obtained from: so (philip)
Tested by: philip, cy
MFC after: immediately
Existing work is underway to import a newer version of heimdal, but
this patchset gets us to a fully working tree to enable more wide
spread testing of OpenSSL 1.1 for now.
I've also enabled WARNS=1 for kerberos (which is the reason for the
change in libroken). Having -Werror enabled was useful during the
1.1 updates and we probably should have warnings enabled by default
for kerberos anyway.
This passes make tinderbox, and I have also done some very light
runtime testing on amd64.
Reviewed by: bjk, jkim, emaste
Differential Revision: https://reviews.freebsd.org/D17276
RFC 4402 specifies the implementation of the gss_pseudo_random()
function for the krb5 mechanism (and the C bindings therein).
The implementation uses a PRF+ function that concatenates the output
of individual krb5 pseudo-random operations produced with a counter
and seed. The original implementation of this function in Heimdal
incorrectly encoded the counter as a little-endian integer, but the
RFC specifies the counter encoding as big-endian. The implementation
initializes the counter to zero, so the first block of output (16 octets,
for the modern AES enctypes 17 and 18) is unchanged. (RFC 4402 specifies
that the counter should begin at 1, but both existing implementations
begin with zero and it looks like the standard will be re-issued, with
test vectors, to begin at zero.)
This is upstream's commit f85652af868e64811f2b32b815d4198e7f9017f6,
from 13 October, 2013:
% Fix krb5's gss_pseudo_random() (n is big-endian)
%
% The first enctype RFC3961 prf output length's bytes are correct because
% the little- and big-endian representations of unsigned zero are the
% same. The second block of output was wrong because the counter was not
% being encoded as big-endian.
%
% This change could break applications. But those applications would not
% have been interoperating with other implementations anyways (in
% particular: MIT's).
Approved by: hrs (mentor, src committer)
MFC after: 3 days
several new kerberos related libraries and applications to FreeBSD:
o kgetcred(1) allows one to manually get a ticket for a particular service.
o kf(1) securily forwards ticket to another host through an authenticated
and encrypted stream.
o kcc(1) is an umbrella program around klist(1), kswitch(1), kgetcred(1)
and other user kerberos operations. klist and kswitch are just symlinks
to kcc(1) now.
o kswitch(1) allows you to easily switch between kerberos credentials if
you're running KCM.
o hxtool(1) is a certificate management tool to use with PKINIT.
o string2key(1) maps a password into key.
o kdigest(8) is a userland tool to access the KDC's digest interface.
o kimpersonate(8) creates a "fake" ticket for a service.
We also now install manpages for some lirbaries that were not installed
before, libheimntlm and libhx509.
- The new HEIMDAL version no longer supports Kerberos 4. All users are
recommended to switch to Kerberos 5.
- Weak ciphers are now disabled by default. To enable DES support (used
by telnet(8)), use "allow_weak_crypto" option in krb5.conf.
- libtelnet, pam_ksu and pam_krb5 are now compiled with error on warnings
disabled due to the function they use (krb5_get_err_text(3)) being
deprecated. I plan to work on this next.
- Heimdal's KDC now require sqlite to operate. We use the bundled version
and install it as libheimsqlite. If some other FreeBSD components will
require it in the future we can rename it to libbsdsqlite and use for these
components as well.
- This is not a latest Heimdal version, the new one was released while I was
working on the update. I will update it to 1.5.2 soon, as it fixes some
important bugs and security issues.
heimdal GSS-API mechanism uses its own version of gssapi.h, including all
the implementation-dependant pollution contained therein.
This moves the file off the vendor branch, sadly.
Submitted by: bz
