Greg Hudson [Mon, 2 Nov 2015 03:45:21 +0000 (22:45 -0500)]
Fix IAKERB context export/import [CVE-2015-2698]
The patches for CVE-2015-2696 contained a regression in the newly
added IAKERB iakerb_gss_export_sec_context() function, which could
cause it to corrupt memory. Fix the regression by properly
dereferencing the context_handle pointer before casting it.
Also, the patches did not implement an IAKERB gss_import_sec_context()
function, under the erroneous belief that an exported IAKERB context
would be tagged as a krb5 context. Implement it now to allow IAKERB
contexts to be successfully exported and imported after establishment.
CVE-2015-2698:
In any MIT krb5 release with the patches for CVE-2015-2696 applied, an
application which calls gss_export_sec_context() may experience memory
corruption if the context was established using the IAKERB mechanism.
Historically, some vulnerabilities of this nature can be translated
into remote code execution, though the necessary exploits must be
tailored to the individual application and are usually quite
complicated.
Greg Hudson [Tue, 27 Oct 2015 04:44:24 +0000 (00:44 -0400)]
Fix two IAKERB comments
The comment explaining why there is no iakerb_gss_import_sec_context()
erroneously referenced SPNEGO instead of IAKERB (noticed by Ben
Kaduk). The comment above iakerb_gss_delete_sec_context() is out of
date after the last commit.
In build_principal_va(), use k5memdup0() instead of strdup() to make a
copy of the realm, to ensure that we allocate the correct number of
bytes and do not read past the end of the input string. This bug
affects krb5_build_principal(), krb5_build_principal_va(), and
krb5_build_principal_alloc_va(). krb5_build_principal_ext() is not
affected.
CVE-2015-2697:
In MIT krb5 1.7 and later, an authenticated attacker may be able to
cause a KDC to crash using a TGS request with a large realm field
beginning with a null byte. If the KDC attempts to find a referral to
answer the request, it constructs a principal name for lookup using
krb5_build_principal() with the requested realm. Due to a bug in this
function, the null byte causes only one byte be allocated for the
realm field of the constructed principal, far less than its length.
Subsequent operations on the lookup principal may cause a read beyond
the end of the mapped memory region, causing the KDC process to crash.
Nicolas Williams [Mon, 14 Sep 2015 16:28:36 +0000 (12:28 -0400)]
Fix IAKERB context aliasing bugs [CVE-2015-2696]
The IAKERB mechanism currently replaces its context handle with the
krb5 mechanism handle upon establishment, under the assumption that
most GSS functions are only called after context establishment. This
assumption is incorrect, and can lead to aliasing violations for some
programs. Maintain the IAKERB context structure after context
establishment and add new IAKERB entry points to refer to it with that
type. Add initiate and established flags to the IAKERB context
structure for use in gss_inquire_context() prior to context
establishment.
CVE-2015-2696:
In MIT krb5 1.9 and later, applications which call
gss_inquire_context() on a partially-established IAKERB context can
cause the GSS-API library to read from a pointer using the wrong type,
generally causing a process crash. Java server applications using the
native JGSS provider are vulnerable to this bug. A carefully crafted
IAKERB packet might allow the gss_inquire_context() call to succeed
with attacker-determined results, but applications should not make
access control decisions based on gss_inquire_context() results prior
to context establishment.
Nicolas Williams [Mon, 14 Sep 2015 16:27:52 +0000 (12:27 -0400)]
Fix SPNEGO context aliasing bugs [CVE-2015-2695]
The SPNEGO mechanism currently replaces its context handle with the
mechanism context handle upon establishment, under the assumption that
most GSS functions are only called after context establishment. This
assumption is incorrect, and can lead to aliasing violations for some
programs. Maintain the SPNEGO context structure after context
establishment and refer to it in all GSS methods. Add initiate and
opened flags to the SPNEGO context structure for use in
gss_inquire_context() prior to context establishment.
CVE-2015-2695:
In MIT krb5 1.5 and later, applications which call
gss_inquire_context() on a partially-established SPNEGO context can
cause the GSS-API library to read from a pointer using the wrong type,
generally causing a process crash. This bug may go unnoticed, because
the most common SPNEGO authentication scenario establishes the context
after just one call to gss_accept_sec_context(). Java server
applications using the native JGSS provider are vulnerable to this
bug. A carefully crafted SPNEGO packet might allow the
gss_inquire_context() call to succeed with attacker-determined
results, but applications should not make access control decisions
based on gss_inquire_context() results prior to context establishment.
In release 1.13, commit eba8c4909ec7ba0d7054d5d1b1061319e9970cc7
(ticket #7232) introduced a memory leak when skipping keytab entries
which do not match the application-provided server specification. Fix
it by freeing the keytab entry before continuing the loop on a failure
to match.
In the mechglue gss_export_sec_context(), make sure to delete the
union context if the underlying mech context has been deleted. This
can happen if the mech's gss_export_sec_context() returns a failure
and deletes the context (not a behavior exhibited by any of our
in-tree mechanisms, but an allowed behavior for other mechs), or if we
fail to allocate space for the wrapped token.
[ghudson@mit.edu: commit message; rename exit label to "cleanup" and
make it valid for all exit cases]
Although our built-in KDB modules do not support client referrals for
AS requests, the KDC is supposed to return one if a third-party module
returns a DB entry containing a principal in a foreign realm.
Unfortunately, this code has never worked; in prepare_error_as(), we
erroneously compare the protocol code errcode against the com_err code
KRB5KDC_ERR_WRONG_REALM; as a result, we never supply the canonical
client principal. Fix this by comparing errcode against the protocol
code KDC_ERR_WRONG_REALM instead.
Solly Ross [Thu, 27 Aug 2015 19:55:35 +0000 (15:55 -0400)]
Check for null name_type in gss_display_name_ext
It is possible for the input name's name_type to be GSS_C_NO_OID.
g_OID_equal() does not account for GSS_C_NO_OID, so we have to
manually check before use to prevent null pointer dereferences.
Before this patch, libkrad would follow the same exact logic for all
socket types when the retries parameter was non-zero. This meant that
when connecting with SOCK_STREAM, multiple requests were sent in case
of packet drops, which, of course, cannot happen for SOCK_STREAM.
Instead, just disable retries for SOCK_STREAM sockets.
Release any previous value of ctx->err_padata before setting it in
init_creds_step_reply(). It could have a prior value after a realm
referral or retriable error.
crypto_retrieve_cert_sans() is allowed to set its princs output to
NULL, although the OpenSSL implementation rarely does. Fix the
TRACE_PKINIT_CLIENT_SAN_KDCCERT_PRINC for loop to allow this like other
parts of the function do, and also get rid of the unnecessary princptr
variable by using an integer index like other parts of the function.
Greg Hudson [Wed, 10 Jun 2015 23:48:51 +0000 (19:48 -0400)]
Tolerate null oid pointer in gss_release_oid()
Under some circumstances, gss_inquire_name() can call
gss_release_oid() with a null oid pointer, which currently causes a
null dereference. The least invasive fix is for gss_release_oid() to
check for the invalid null pointer and return an error, like other
GSS-API functions do.
Ben Kaduk [Wed, 24 Jun 2015 17:34:32 +0000 (13:34 -0400)]
Make the Principal column wider by default
The current 100-pixel default is too small to fit most principal
names (particularly the realm). There is no reason why all the
columns must be the same width, so promote this one as needing
more space.
Ben Kaduk [Tue, 23 Jun 2015 14:38:19 +0000 (10:38 -0400)]
Make registry hostrealm module highest precedence
Testing reveals that there are a number of machines in the wild
which retain old krb5.ini files across domain configuration changes,
and it is difficult to determine which machines are potentially
affected by incorrect stale configuration data.
To enable domain administrators to easily ensure that the correct
default realm is set, allow the registry hostrealm module to take
precedence over the profile.
Note that the registry hostrealm module can still be disabled
in the hostrealm interface configuration statment in the
[plugins] section of the profile.
Ben Kaduk [Fri, 29 May 2015 18:46:58 +0000 (14:46 -0400)]
Stop using the WiX src attribute
The src attribute has been deprecated for a while in favor of
different (more descriptive) attributes for the different XML
elements involved.
For the File element, use the Source attribute.
For the Directory element, use the FileSource attribute.
For the Merge, Binary, and Text elements, use the SourceFile attribute.
This makes the installer build much quieter, with the warnings from
the light.exe invocation all fitting into the default history buffer.
Ben Kaduk [Wed, 27 May 2015 19:36:51 +0000 (15:36 -0400)]
Stop using the WiX Registry element
It is deprecated in favor of more specific XML elements such
as RegistryKey, RegistryValue, and RemoveRegistryKey, so as to
stop overloading a single element for what are fundamentally
different types and operations.
RegistryValue elements can be children of RegistryKey elements,
allowing the Key attribute to be inherited, or bare within the
containing Component. We do not take advantage of the inheritance
at this time, since that would be a more disruptive change.
WiX would prefer for us to not use the createAndRemoveOnUninstall
attribute of <RegistryKey>, in favor of ForceCreateOnInstall
and/or ForceRemoveOnUninstall, but that can wait for a follow-up
commit.
Some instances of <Registry> were commented-out and can simply be
removed.
Some of the <Registry> elements used to create keys were also
setting the KeyPath attribute, which is not permitted in the
<RegistryKey> element. According to
http://sourceforge.net/p/wix/bugs/3197/ , this should never have
been allowed, and non-value registry keys should not be used as
MSI KeyPaths. In all affected cases, there are child
RegistryValue elements that are suitable for use as KeyPath
elements instead.
Some of the <Registry> elements were present with a duplicate
element with different Id that added no new attributes; those
duplicate elements can safely be removed.
<RemoveRegistryKey> is used to replace <Registry> elements
with Action=removeKeyOnInstall.
Ben Kaduk [Mon, 22 Jun 2015 23:11:28 +0000 (19:11 -0400)]
Put focus on password field when principal is set
In the Leash "Get Ticket" window, under some user-customized
configurations, the principal field can be pre-populated. In this case,
it makes sense for the default focus to be on the password field,
since most users will only be using a single principal and should
go directly to typing their password.
The focus was already set to the password field in the case when
the principal was not modifiable (such as when the "Get Ticket" dialog
was opened by an application requesting a specific ticket).
Ben Kaduk [Fri, 22 May 2015 18:38:27 +0000 (14:38 -0400)]
Add leash column for the ccache name
Previously, it was fairly easy to set the default cache to MSLSA:,
which is not collection-enabled (as opposed to the normal default
of API:, which is), and the non-collection behavior proved confusing
to many users.
Ideally there would be an option to choose the output ccache in
the "Get Ticket" window, but that is more complicated to implement
than just a display of what cache a given ticket is in. This
extra display column should still help to alleviate user confusion.
Ben Kaduk [Fri, 22 May 2015 18:42:02 +0000 (14:42 -0400)]
Make ribbon home tab more pretty
In the absence of a label title for a given command group, the
text "MS Shell Dlg" was inserted, which is somewhat confusing to
the user. Give the ticket-maniuplation group a title consisting
of a space, which removes the confusing text from the display.
Ben Kaduk [Mon, 11 May 2015 17:08:42 +0000 (13:08 -0400)]
Reboot after KfW installs to help the LSA cache
It seems that we need to restart in order to be able to query the
contents of the the LSA cache, even if the only contents of the LSA
cache are what we put there, and even if the Microsoft klist.exe
correctly reports the presence of tickets in the LSA cache.
Ben Kaduk [Tue, 5 May 2015 20:55:41 +0000 (16:55 -0400)]
Supply a hostrealm module to query the registry
Implement a default_realm function that checks the
{HKLM,HKCU}\Software\MIT\Kerberos5\default_realm registry values
on Windows, and just returns KRB5_PLUGIN_NO_HANDLE on Unix.
Ben Kaduk [Fri, 6 Mar 2015 20:42:10 +0000 (15:42 -0500)]
Fix loop to determine MSLSA principal name
When looping over principals, check the i-th entry instead of
looking at the 0-th entry each time through the loop. This would
only affect cases when multiple ticket entries were returned from
the LSA, the first one did not have a valid principal name, but
some other one did. It is expected that all of the returned
ticket entries will always have a valid client principal name, so
this is unlikely to cause any functional difference.
Ben Kaduk [Wed, 5 Dec 2012 17:15:07 +0000 (12:15 -0500)]
KfW shortcuts for make default, change password
Shortcut keys such as these (in the ACCELERATORS entry in the resource
file) are what let users type, e.g., ctrl-t to get to the "get tickets"
dialog directly from the main frame. We had shortcut keys for all the
other buttons already, so add these to complete the set.
The make default and change password functionality were already available
using keyboard-only interfaces via the ribbon access keys (tap alt,
then letters to walk through the tree of controls), but the two forms
of keyboard access are implemented differently.
Ben Kaduk [Fri, 10 Apr 2015 21:33:40 +0000 (17:33 -0400)]
Switch to Windows SDK Ribbon from MFC Ribbon
The MFC Ribbon implementation is not very accessible (e.g., to
screen reading software), whereas the windows ribbon provides
essentially the same functionality and good integration with
screen reading software, including the built-in Windows Narrator.
Remove the RT_RIBBON_XML resource from the resource file and
replace it with an inclusion of the generated kfwribbon.rc file.
Also remove the ribbon1.mfcribbon-ms ribbon description from the
res/ directory. Add the appropriate dependency relation in the
Makefile.
LeashUIApplication implements the IUIUApplication interfaces. It
appears to be difficult to cleanly tear down the underlying
IUIFramework and ribbon, since the WM_DESTROY event is handled by the
parent MFC window, which will not call IUIFramework::Destroy().
Manually inserting a call to IUIFramework::Destroy() in the shutdown
handling of the MFC classes is difficult, since the WM_DESTROY message
is handled by a different window than where the ribbon is initialized,
and the MFC framework will attempt to access window objects
corresponding to the UI Ribbon resources after they are destroyed,
which raises exceptions. It seems best to just go without destroying
the IUIFramework, since its lifecycle matches that of the application
and there will be no leaks during the application lifecycle.
LeashUICommandHandler implements the IUICommandHandler interfaces,
passing messages through to the existing MFC handlers, though the
default values for the various checkbox controls must be duplicated.
The (MFC) CMainFrame creates and maintains a handle to the
LeashUIApplication associated with the ribbon it creates, so that
it can query the height of the ribbon and redraw when the
LeashUIApplication signals that the ribbon size has changed.
Record that the added object files depend on kfwribbon.h, so that
the XML markup is compiled sufficiently early in the build.
Ben Kaduk [Thu, 19 Mar 2015 18:14:02 +0000 (14:14 -0400)]
Mention Visual Studio 2010 SP1 in windows README
The service pack is needed to avoid a linker error due to an
issue with the cvtres.exe utility, which manifests as
LINK: fatal error LNK1123: failure during conversion to COFF: file
invalid or corrupt.
Benjamin Kaduk [Fri, 17 Jan 2014 21:02:13 +0000 (16:02 -0500)]
XML Ribbon markup file
The standard windows library ribbon interface is either constructed
at runtime or specified in an XML file. Since we have a static
set of functionality in our ribbon, it is simplest to just use the
XML file.
This should duplicate the interfaces currently provided by the
MFC ribbon, though the menu items in the file menu are slightly
taller than they used to be.
Use uicc.exe to compile the XML to the binary format and produce
a kfwribon.rc resource file and kfwribbon.h header.
Benjamin Kaduk [Mon, 27 Jan 2014 18:07:38 +0000 (13:07 -0500)]
Import separate large ribbon bitmaps
This is the content from homelarge.bmp split up into the
separate component images, since the windows ribbon has the
(more sane) interface of using a separate resource for each
graphic, instead of expecting them all in a single bitmap which
is sliced up at runtime.
The bitmaps are required to have alpha channels, and it seems that
the easiest way to generate bitmaps with alpha channels is to use
Microsoft Paint, since the normal Unix open-source graphics tools
do not want to output this format.
Benjamin Kaduk [Wed, 22 Jan 2014 05:05:57 +0000 (00:05 -0500)]
Remove MBCS from leash's DEFINES
This is just enabling the use of multi-byte character set in the
MFC library, but we do not appear to make use of this feature.
Visual Studio 2013 gives ominous warnings that support for it may
be removed in future versions, so quiet the build and do not
enable the deprecated feature we are not using.
Ben Kaduk [Tue, 14 Apr 2015 19:33:20 +0000 (15:33 -0400)]
Fix leash crash found in some build environments
When freeing a credentials cache name obtained from
krb5_cc_get_full_name(), the code was using plain free()
instead of the matching krb5_free_string(). If these routines
are picked from different modules at runtime, the mismatch
will cause a crash in free(), so change to using the matched
deallocation function.
In order to use it in leash, it must be declared in Lglobals.h and
the function pointer symbol defined in Leash.cpp.
Ben Kaduk [Thu, 14 Aug 2014 17:57:48 +0000 (13:57 -0400)]
Avoid unneeded GetMSTGT() calls in cc_mslsa.c
Both lcc_resolve() and lcc_get_principal() were using GetMSTGT()
to fetch a ticket from which to obtain the client principal name
of the credentials cache. However, that name is contained in
the results of the the cache information query; there is no need
to retrieve a full ticket of any sort to get it. Since there
may sometimes be difficulties obtaining a TGT when UAC is enabled,
avoid these unneeded calls.
Ben Kaduk [Wed, 13 Aug 2014 20:28:57 +0000 (16:28 -0400)]
Remove unused code from cc_mslsa.c
Remove PreserveInitialTicketIdentity() and IsKerberosLogon(), as well
as the preprocessor conditionals ENABLE_PURGING and PURGE_ALL, which
have not been used in a very long time, if ever.
There was one potential callsite of IsKerberosLogon(), in
lcc_resolve(), which was disabled. It is perfectly reasonable to want
to use the MSLSA cache on a non-domain-joined workstation, as it is
now a read-write cache type, so we need not concern ourselves whether
the logon was performed or may have been performed using kerberos.
Ben Kaduk [Wed, 13 Aug 2014 20:31:49 +0000 (16:31 -0400)]
comment some future cleanup for cc_mslsa.c
The function does_query_ticket_cache_ex2() will not be needed once
Windows Server 2003 drops out of support in approximately one year's
time. Note the doom timer at its definition, to facilitate future
cleanup.
Ben Kaduk [Wed, 13 Aug 2014 16:54:37 +0000 (12:54 -0400)]
Remove old Windows support from cc_mslsa.c
It is safe to remove is_windows_2000(), is_windows_xp(), and
is_windows_vista(), since the former two only check for very old
versions of windows which are no longer supported, and
is_windows_vista() was unused. Note that the check being implemented
was whether the running OS was the named version or higher, not an
exact match. The current Microsoft documentation recommends against
the sort of OS version checks that were employed here, in favor of
explicit feature tests.
Remove is_broken_wow64() as the problem it works around (Microsoft
Article ID 960077) is believed to have been fixed in subsequent
updates to Windows Server 2003 and XP.
Remove does_retrieve_ticket_cache_ticket() since support for the
KERB_RETRIEVE_TICKET_CACHE_TICKET flag in the
KERB_RETRIEVE_TKT_REQUEST structure was added in service packs for
Windows Server 2003 and XP. Also remove buildtime fallbacks that
are no longer needed.
Remove the conditionals TRUST_ATTRIBUTE_TRUST_USES_AES_KEYS,
HAVE_CACHE_INFO_EX2, and KERB_SUBMIT_TICKET as all current SDK
versions have the relevant functionality.
In all cases, de-indent chunks that are no longer conditional.
Where indentation levels changed, update the style of the reindented
code to current practices.
Greg Hudson [Tue, 24 Mar 2015 16:02:37 +0000 (12:02 -0400)]
Prevent requires_preauth bypass [CVE-2015-2694]
In the OTP kdcpreauth module, don't set the TKT_FLG_PRE_AUTH bit until
the request is successfully verified. In the PKINIT kdcpreauth
module, don't respond with code 0 on empty input or an unconfigured
realm. Together these bugs could cause the KDC preauth framework to
erroneously treat a request as pre-authenticated.
CVE-2015-2694:
In MIT krb5 1.12 and later, when the KDC is configured with PKINIT
support, an unauthenticated remote attacker can bypass the
requires_preauth flag on a client principal and obtain a ciphertext
encrypted in the principal's long-term key. This ciphertext could be
used to conduct an off-line dictionary attack against the user's
password.
krb5_ldap_get_value() takes a pointer to int, and should not be passed
a pointer to any integral type which might have a different width.
Use an intermediate variable for each call.
The erroneous calls in ldap_misc.c were passing pointers to int32_t,
which is harmless on all common platforms. The calls in
ldap_tkt_policy.c were passing pointers to long; on big-endian LP64
platforms, the result would be written to the high 32 bits of the long
value.
Greg Hudson [Thu, 26 Mar 2015 16:47:06 +0000 (12:47 -0400)]
Disable principal renames for LDAP
The current principal rename procedure does not work with the LDAP KDB
module, instead having the effect of deleting the principal. The fix
is not easy and requires amending the DAL (see issue #8065). For now,
detect LDAP and error out when a rename operation is attempted.
Greg Hudson [Fri, 13 Mar 2015 17:30:49 +0000 (13:30 -0400)]
Log invalid restrictions strings
In kadm5int_acl_parse_restrictions(), output a log message if we break
out of the parsing loop with an error. The current structure of the
loop makes it difficult to pinpoint the bad restrictions field, so
just output the whole string.
Greg Hudson [Fri, 13 Mar 2015 16:45:27 +0000 (12:45 -0400)]
Document correct flag names for kadm5.acl
kadm5.acl entries can include restrictions which can force flag values
on or off. These flag values are parsed with krb5_string_to_flags(),
which means the flag names are the ones for default_principal_flags,
not the ones for kadmin addprinc/modprinc.
Greg Hudson [Thu, 12 Mar 2015 20:36:33 +0000 (16:36 -0400)]
Fix scope of kadmind ACL wildcard back-references
In kadm5int_acl_find_entry(), clear the wildcard back-references list
for each acl entry. Otherwise the wildcards we process can affect
back-references for later entries.
Solly Ross [Thu, 5 Mar 2015 18:22:58 +0000 (13:22 -0500)]
Import names immediately with COMPOSITE_EXPORT
RFC 6680 specifies that GSS_Export_name_composite() "outputs a token that
"can be imported with GSS_Import_name(), using GSS_C_NT_COMPOSITE_EXPORT
as the name type...". Therefore, in the gss_import_name mechglue, we
should perform the import process imediately when either
GSS_C_NT_COMPOSITE_EXPORT or GSS_C_NT_EXPORT_NAME are used (not just
for the later, as is the current functionality).
The naming extension test was also updated to display the result
of importing with GSS_C_NT_COMPOSITE_EXPORT in addition to
GSS_C_NT_EXPORT_NAME.
Greg Hudson [Tue, 9 Dec 2014 17:37:44 +0000 (12:37 -0500)]
Fix krb5_read_message handling [CVE-2014-5355]
In recvauth_common, do not use strcmp against the data fields of
krb5_data objects populated by krb5_read_message(), as there is no
guarantee that they are C strings. Instead, create an expected
krb5_data value and use data_eq().
In the sample user-to-user server application, check that the received
client principal name is null-terminated before using it with printf
and krb5_parse_name.
CVE-2014-5355:
In MIT krb5, when a server process uses the krb5_recvauth function, an
unauthenticated remote attacker can cause a NULL dereference by
sending a zero-byte version string, or a read beyond the end of
allocated storage by sending a non-null-terminated version string.
The example user-to-user server application (uuserver) is similarly
vulnerable to a zero-length or non-null-terminated principal name
string.
The krb5_recvauth function reads two version strings from the client
using krb5_read_message(), which produces a krb5_data structure
containing a length and a pointer to an octet sequence. krb5_recvauth
assumes that the data pointer is a valid C string and passes it to
strcmp() to verify the versions. If the client sends an empty octet
sequence, the data pointer will be NULL and strcmp() will dereference
a NULL pointer, causing the process to crash. If the client sends a
non-null-terminated octet sequence, strcmp() will read beyond the end
of the allocated storage, possibly causing the process to crash.
uuserver similarly uses krb5_read_message() to read a client principal
name, and then passes it to printf() and krb5_parse_name() without
verifying that it is a valid C string.
The krb5_recvauth function is used by kpropd and the Kerberized
versions of the BSD rlogin and rsh daemons. These daemons are usually
run out of inetd or in a mode which forks before processing incoming
connections, so a process crash will generally not result in a
complete denial of service.
Tom Yu [Wed, 4 Feb 2015 22:01:14 +0000 (17:01 -0500)]
Avoid uninitialized data in t_prf.c
In t_prf.c, make sure that the partially initialized, faked-up
structures gss_union_ctx_id_desc and krb5_gss_ctx_id_rec are zeroed.
This avoids uninitialized reads in gss_pseudo_random(), which can
cause intermittent test failures on some platforms.
Greg Hudson [Wed, 4 Feb 2015 18:03:20 +0000 (13:03 -0500)]
Bump DAL major version for iterate change
Commit ab009b8568d9b64b7e992ecdb98114e895b4a7ff for issue #7977
changed the signature of krb5_db_iterate() and properly bumped
KRB5_KDB_API_VERSION from 7 to 8. It also changed the signature of
the DAL iterate() function, but did not bump
KRB5_KDB_DAL_MAJOR_VERSION. Bump that version from 4 to 5 now.
Greg Hudson [Mon, 29 Dec 2014 18:17:56 +0000 (13:17 -0500)]
Fix gssrpc data leakage [CVE-2014-9423]
[MITKRB5-SA-2015-001] In svcauth_gss_accept_sec_context(), do not copy
bytes from the union context into the handle field we send to the
client. We do not use this handle field, so just supply a fixed
string of "xxxx".
In gss_union_ctx_id_struct, remove the unused "interposer" field which
was causing part of the union context to remain uninitialized.
Greg Hudson [Mon, 29 Dec 2014 18:27:42 +0000 (13:27 -0500)]
Fix kadmind server validation [CVE-2014-9422]
[MITKRB5-SA-2015-001] In kadmind's check_rpcsec_auth(), use
data_eq_string() instead of strncmp() to check components of the
server principal, so that we don't erroneously match left substrings
of "kadmin", "history", or the realm.
Greg Hudson [Sat, 27 Dec 2014 19:16:13 +0000 (14:16 -0500)]
Fix kadm5/gssrpc XDR double free [CVE-2014-9421]
[MITKRB5-SA-2015-001] In auth_gssapi_unwrap_data(), do not free
partial deserialization results upon failure to deserialize. This
responsibility belongs to the callers, svctcp_getargs() and
svcudp_getargs(); doing it in the unwrap function results in freeing
the results twice.
In xdr_krb5_tl_data() and xdr_krb5_principal(), null out the pointers
we are freeing, as other XDR functions such as xdr_bytes() and
xdr_string().
Greg Hudson [Wed, 5 Nov 2014 16:58:04 +0000 (11:58 -0500)]
Fix gss_process_context_token() [CVE-2014-5352]
[MITKRB5-SA-2015-001] The krb5 gss_process_context_token() should not
actually delete the context; that leaves the caller with a dangling
pointer and no way to know that it is invalid. Instead, mark the
context as terminated, and check for terminated contexts in the GSS
functions which expect established contexts. Also add checks in
export_sec_context and pseudo_random, and adjust t_prf.c for the
pseudo_random check.
Simo Sorce [Tue, 20 Jan 2015 18:48:34 +0000 (13:48 -0500)]
Do not loop on principal unknown errors
If the canonicalize flag is set, the MIT KDC always return the client
principal when KRB5_KDC_ERR_C_PRICIPAL_UNKNOWN is returned.
Check that this is really a referral by testing that the returned
client realm differs from the requested one.
[ghudson@mit.edu: simplified and narrowed is_referral() contract.
Note that a WRONG_REALM response with e-data or FAST error padata
could now be passed through k5_preauth_tryagain() if it has an empty
crealm or a crealm equal to the requested client realm. Such a
response is unexpected in practice and there is nothing dangerous
about handling it this way.]
Greg Hudson [Wed, 14 Jan 2015 18:10:39 +0000 (13:10 -0500)]
Check for null *iter_p in profile_iterator()
In profile_iterator(), return PROF_MAGIC_ITERATOR if *iter_p is NULL,
instead of dereferencing a null pointer, as we did prior to 1.10.
Correct calling code will not trigger this case, but incorrect code
has been reported in the field.
Ben Kaduk [Wed, 19 Nov 2014 17:04:46 +0000 (12:04 -0500)]
Support keyless principals in LDAP [CVE-2014-5354]
Operations like "kadmin -q 'addprinc -nokey foo'" or
"kadmin -q 'purgekeys -all foo'" result in principal entries with
no keys present, so krb5_encode_krbsecretkey() would just return
NULL, which then got unconditionally dereferenced in
krb5_add_ber_mem_ldap_mod().
Apply some fixes to krb5_encode_krbsecretkey() to handle zero-key
principals better, correct the test for an allocation failure, and
slightly restructure the cleanup handler to be shorter and more
appropriate for the usage. Once it no longer short-circuits when
n_key_data is zero, it will produce an array of length two with both
entries NULL, which is treated as an empty list by the LDAP library,
the correct behavior for a keyless principal.
However, attributes with empty values are only handled by the LDAP
library for Modify operations, not Add operations (which only get
a sequence of Attribute, with no operation field). Therefore, only
add an empty krbprincipalkey to the modlist when we will be performing a
Modify, and not when we will be performing an Add, which is conditional
on the (misspelled) create_standalone_prinicipal boolean.
CVE-2014-5354:
In MIT krb5, when kadmind is configured to use LDAP for the KDC
database, an authenticated remote attacker can cause a NULL
dereference by inserting into the database a principal entry which
contains no long-term keys.
In order for the LDAP KDC backend to translate a principal entry
from the database abstraction layer into the form expected by the
LDAP schema, the principal's keys are encoded into a
NULL-terminated array of length-value entries to be stored in the
LDAP database. However, the subroutine which produced this array
did not correctly handle the case where no keys were present,
returning NULL instead of an empty array, and the array was
unconditionally dereferenced while adding to the list of LDAP
operations to perform.
Versions of MIT krb5 prior to 1.12 did not expose a way for
principal entries to have no long-term key material, and
therefore are not vulnerable.
Greg Hudson [Fri, 5 Dec 2014 19:01:39 +0000 (14:01 -0500)]
Fix LDAP misused policy name crash [CVE-2014-5353]
In krb5_ldap_get_password_policy_from_dn, if LDAP_SEARCH returns
successfully with no results, return KRB5_KDB_NOENTRY instead of
returning success with a zeroed-out policy object. This fixes a null
dereference when an admin attempts to use an LDAP ticket policy name
as a password policy name.
CVE-2014-5353:
In MIT krb5, when kadmind is configured to use LDAP for the KDC
database, an authenticated remote attacker can cause a NULL dereference
by attempting to use a named ticket policy object as a password policy
for a principal. The attacker needs to be authenticated as a user who
has the elevated privilege for setting password policy by adding or
modifying principals.
Queries to LDAP scoped to the krbPwdPolicy object class will correctly
not return entries of other classes, such as ticket policy objects, but
may return success with no returned elements if an object with the
requested DN exists in a different object class. In this case, the
routine to retrieve a password policy returned success with a password
policy object that consisted entirely of zeroed memory. In particular,
accesses to the policy name will dereference a NULL pointer. KDC
operation does not access the policy name field, but most kadmin
operations involving the principal with incorrect password policy
will trigger the crash.
Greg Hudson [Mon, 8 Dec 2014 20:30:25 +0000 (15:30 -0500)]
Fix LDAP tests when sasl.h not found
Do not try to run the SASL EXTERNAL auth test if we could not define a
useful interact function. With current libraries the interact
function is asked for an authorization name, and the bind fails if it
gets an unsuccessful result or if no interaction function is defined.
Ben Kaduk [Thu, 20 Nov 2014 20:44:04 +0000 (15:44 -0500)]
Avoid infinite loop on duplicate keysalts
When duplicate suppression was requested, we would enter an
infinite loop upon encountering a duplicate entry, a bug
introduced in commit 0918990bf1d8560d74473fc0e41d08d433da1a15
and thus present in release 1.13.
Rework the conditional to avoid the loop, at the expense of
additional indentation for some of the code.
Greg Hudson [Wed, 5 Nov 2014 19:12:35 +0000 (14:12 -0500)]
Fix input race condition in t_skew.py
In two of the kinit tests run by t_skew.py, we expect kinit to exit
before reading the password. If we supply a password input for those
commands, we can fail with a broken pipe exception if the master
process tries to write the password after the slave process exits.
Also correctly check the output of the last kinit invocation.
Greg Hudson [Wed, 29 Oct 2014 16:16:40 +0000 (12:16 -0400)]
Remove length limit on PKINIT PKCS#12 prompt
Long pathnames can trigger the 128-byte prompt length limit in
pkinit_get_certs_pkcs12. Use asprintf instead of snprintf. Also
check the result of the prompter invocation.
Greg Hudson [Mon, 20 Oct 2014 16:52:45 +0000 (12:52 -0400)]
Report output ccache errors getting initial creds
In init_creds_step_reply, if we get an error storing output
credentials, do set ctx->complete (since retrieving creds or times
will work at this point) but don't suppress the error code.
Tom Yu [Thu, 16 Oct 2014 19:40:33 +0000 (15:40 -0400)]
Parse "ktadd -norandkey" in remote kadmin client
The remote kadmin client would not parse the "-norandkey" option to
the ktadd subcommand, terminating option parsing and possibly causing
options to be interpreted as principal names.
Greg Hudson [Wed, 8 Oct 2014 00:22:52 +0000 (20:22 -0400)]
Use gssalloc_malloc for GSS error tokens
In kg_accept_krb5, use gssalloc_malloc when allocating space for the
error token, since it will be freed with gssalloc_free. Using malloc
can cause heap corruption on Windows. This bug was masked by #1445
before 1.12.
projects / thirdparty / krb5.git / log
