Synopsis

Low: sssd security, bug fix, and enhancement update

Type/Severity

Security Advisory: Low

Topic

Updated sssd packages that fix one security issue, multiple bugs, and add
various enhancements are now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having Low security
impact. A Common Vulnerability Scoring System (CVSS) base score, which
gives a detailed severity rating, is available from the CVE link in the
References section.

Description

The System Security Services Daemon (SSSD) service provides a set of
daemons to manage access to remote directories and authentication
mechanisms.

It was found that SSSD's Privilege Attribute Certificate (PAC) responder
plug-in would leak a small amount of memory on each authentication request.
A remote attacker could potentially use this flaw to exhaust all available
memory on the system by making repeated requests to a Kerberized daemon
application configured to authenticate using the PAC responder plug-in.
(CVE-2015-5292)

The sssd packages have been upgraded to upstream version 1.13.0, which
provides a number of bug fixes and enhancements over the previous version.
(BZ#1205554)

Several enhancements are described in the Red Hat Enterprise Linux 7.2
Release Notes, linked to in the References section:

• SSSD smart card support (BZ#854396)
• Cache authentication in SSSD (BZ#910187)
• SSSD supports overriding automatically discovered AD site (BZ#1163806)
• SSSD can now deny SSH access to locked accounts (BZ#1175760)
• SSSD enables UID and GID mapping on individual clients (BZ#1183747)
• Background refresh of cached entries (BZ#1199533)
• Multi-step prompting for one-time and long-term passwords (BZ#1200873)
• Caching for initgroups operations (BZ#1206575)

Bugs fixed:

• When the SELinux user content on an IdM server was set to an empty

string, the SSSD SELinux evaluation utility returned an error. (BZ#1192314)

• If the ldap_child process failed to initialize credentials and exited

with an error multiple times, operations that create files in some cases
started failing due to an insufficient amount of i-nodes. (BZ#1198477)

• The SRV queries used a hard coded TTL timeout, and environments that

wanted the SRV queries to be valid for a certain time only were blocked.
Now, SSSD parses the TTL value out of the DNS packet. (BZ#1199541)

• Previously, initgroups operation took an excessive amount of time. Now,

logins and ID processing are faster for setups with AD back end and
disabled ID mapping. (BZ#1201840)

• When an IdM client with Red Hat Enterprise Linux 7.1 or later was

connecting to a server with Red Hat Enterprise Linux 7.0 or earlier,
authentication with an AD trusted domain caused the sssd_be process to
terminate unexpectedly. (BZ#1202170)

• If replication conflict entries appeared during HBAC processing, the user

was denied access. Now, the replication conflict entries are skipped and
users are permitted access. (BZ#1202245)

• The array of SIDs no longer contains an uninitialized value and SSSD no

longer crashes. (BZ#1204203)

• SSSD supports GPOs from different domain controllers and no longer

crashes when processing GPOs from different domain controllers.
(BZ#1205852)

• SSSD could not refresh sudo rules that contained groups with special

characters, such as parentheses, in their name. (BZ#1208507)

• The IPA names are not qualified on the client side if the server already

qualified them, and IdM group members resolve even if default_domain_suffix
is used on the server side. (BZ#1211830)

• The internal cache cleanup task has been disabled by default to improve

performance of the sssd_be process. (BZ#1212489)

• Now, default_domain_suffix is not considered anymore for autofs maps.

(BZ#1216285)

• The user can set subdomain_inherit=ignore_group-members to disable

fetching group members for trusted domains. (BZ#1217350)

• The group resolution failed with an error message: "Error: 14 (Bad

address)". The binary GUID handling has been fixed. (BZ#1226119)

Enhancements added:

• The description of default_domain_suffix has been improved in the manual

pages. (BZ#1185536)

• With the new "%0" template option, users on SSSD IdM clients can now use

home directories set on AD. (BZ#1187103)

All sssd users are advised to upgrade to these updated packages, which
correct these issues and add these enhancements.

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.4 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.3 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.3 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux Server from RHUI 7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.3 x86_64
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.6 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.5 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.4 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.3 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.2 ppc64le
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.3 x86_64
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.7 ppc64le
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.6 ppc64le
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.4 ppc64le
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.3 ppc64le
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.4 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.3 x86_64

Fixes

• BZ - 854396 - [RFE] Support for smart cards
• BZ - 1007968 - sssd does not create AAAA record in AD
• BZ - 1163806 - [RFE]ad provider dns_discovery_domain option: kerberos discovery is not using this option
• BZ - 1187103 - [RFE] User's home directories are not taken from AD when there is an IPA trust with AD
• BZ - 1187146 - If v4 address exists, will not create nonexistant v6 in ipa domain
• BZ - 1192314 - With empty ipaselinuxusermapdefault security context on client is staff_u
• BZ - 1199445 - Does sssd-ad use the most suitable attribute for group name?
• BZ - 1200873 - [RFE] Allow smart multi step prompting when user logs in with password and token code from IPA
• BZ - 1201840 - SSSD downloads too much information when fetching information about groups
• BZ - 1202245 - SSSD's HBAC processing is not permissive enough with broken replication entries
• BZ - 1202724 - [RFE] Add a way to lookup users based on CAC identity certificates
• BZ - 1203642 - GPO access control looks for computer object in user's domain only
• BZ - 1205144 - RFE: Support one-way trusts for IPA
• BZ - 1205160 - Complain loudly if backend doesn't start due to missing or invalid keytab
• BZ - 1205554 - Rebase SSSD to 1.13.x
• BZ - 1206189 - [bug] sssd always appends default_domain_suffix when checking for host keys
• BZ - 1206565 - [RFE] Add dualstack and multihomed support
• BZ - 1206566 - SSSD does not update Dynamic DNS records if the IPA domain differs from machine hostname's domain
• BZ - 1206571 - [RFE] Expose D-BUS interface
• BZ - 1211830 - external users do not resolve with "default_domain_suffix" set in IPA server sssd.conf
• BZ - 1214337 - Overrides with --login work in second attempt
• BZ - 1214716 - idoverridegroup for ipa group with --group-name does not work
• BZ - 1214718 - Overridde with --login fails trusted adusers group membership resolution
• BZ - 1214719 - Group resolution is inconsistent with group overrides
• BZ - 1216285 - autofs provider fails when default_domain_suffix and use_fully_qualified_names set
• BZ - 1217127 - Override for IPA users with login does not list user all groups
• BZ - 1217559 - [RFE] Support GPOs from different domain controllers
• BZ - 1219285 - Unable to resolve group memberships for AD users when using sssd-1.12.2-58.el7_1.6.x86_64 client in combination with ipa-server-3.0.0-42.el6.x86_64 with AD Trust
• BZ - 1234722 - sssd ad provider fails to start in rhel7.2
• BZ - 1242942 - well-known SID check is broken for NetBIOS prefixes
• BZ - 1244949 - getgrgid for user's UID on a trust client prevents getpw*
• BZ - 1246489 - sss_obfuscate fails with "ImportError: No module named pysss"
• BZ - 1249015 - KDC proxy not working with SSSD krb5_use_kdcinfo enabled
• BZ - 1250135 - Detect re-established trusts in the IPA subdomain code
• BZ - 1254184 - sss_override does not work correctly when 'use_fully_qualified_names = True'
• BZ - 1254189 - sss_override contains an extra parameter --debug but is not listed in the man page or in the arguments help
• BZ - 1254518 - Fix crash in nss responder
• BZ - 1259512 - sss_override : The local override user is not found
• BZ - 1261155 - nsupdate exits on first GSSAPI error instead of processing other commands
• BZ - 1263587 - sss_override --name doesn't work with RFC2307 and ghost users
• BZ - 1263735 - Could not resolve AD user from root domain
• BZ - 1266107 - AD: Conditional jump or move depends on uninitialised value
• BZ - 1267176 - Memory leak / possible DoS with krb auth. [rhel 7.2]
• BZ - 1267580 - CVE-2015-5292 sssd: memory leak in the sssd_pac_plugin
• BZ - 1267836 - PAM responder crashed if user was not set
• BZ - 1267837 - sssd_be crashed in ipa_srv_ad_acct_lookup_step
• BZ - 1270827 - local overrides: don't contact server with overridden name/id

CVEs

• CVE-2015-5292

References