The svcauth_gss_accept_sec_context function in lib/rpc/svc_auth_gss.c in MIT Kerberos 5 (aka krb5) 1.11.x through 1.11.5, 1.12.x through 1.12.2, and 1.13.x before 1.13.1 transmits uninitialized interposer data to clients, which allows remote attackers to obtain sensitive information from process heap memory by sniffing the network for data in a handle field.

The version of the Network Authentication Service (NAS) installed on the remote AIX host is affected by the following vulnerabilities related to Kerberos 5 :

  - Denial of service and remote code execution     vulnerabilities exist due to security context handles     not being properly maintained, allowing an     authenticated, remote attacker to crash the service or     execute arbitrary code using crafted GSSAPI traffic.
    (CVE-2014-5352)

  - A denial of service vulnerability exists due to improper     handling of zero-byte or unterminated strings.
    (CVE-2014-5355)

  - Denial of service and remote code execution     vulnerabilities exist which allow an authenticated,     remote attacker to crash the service or execute     arbitrary code using crafted, malformed XDR data.
    (CVE-2014-9421)

  - A privilege escalation vulnerability exists that allows     an authenticated, remote attacker to gain administrative     access via a flaw in kadmin authorization checks.
    (CVE-2014-9422)

  - An information disclosure vulnerability allows an     attacker to gain information about process heap memory     from NAS packets. (CVE-2014-9423)

MIT kerberos krb5 was updated to fix several security issues and bugs.

Security issues fixed: CVE-2014-5351: The kadm5_randkey_principal_3 function in lib/kadm5/srv/svr_principal.c in kadmind in MIT Kerberos 5 (aka krb5) sent old keys in a response to a -randkey -keepold request, which allowed remote authenticated users to forge tickets by leveraging administrative access.

  - CVE-2014-5352: In the MIT krb5 libgssapi_krb5 library,     after gss_process_context_token() is used to process a     valid context deletion token, the caller was left with a     security context handle containing a dangling pointer.
    Further uses of this handle would have resulted in     use-after-free and double-free memory access violations.
    libgssrpc server applications such as kadmind were     vulnerable as they can be instructed to call     gss_process_context_token().

  - CVE-2014-9421: If the MIT krb5 kadmind daemon receives     invalid XDR data from an authenticated user, it may have     performed use-after-free and double-free memory access     violations while cleaning up the partial deserialization     results. Other libgssrpc server applications might also     been vulnerable if they contain insufficiently defensive     XDR functions.

  - CVE-2014-9422: The MIT krb5 kadmind daemon incorrectly     accepted authentications to two-component server     principals whose first component is a left substring of     'kadmin' or whose realm is a left prefix of the default     realm.

  - CVE-2014-9423: libgssrpc applications including kadmind     output four or eight bytes of uninitialized memory to     the network as part of an unused 'handle' field in     replies to clients.

Bugs fixed :

  - Work around replay cache creation race; (bnc#898439).

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Multiple vulnerabilities has been discovered and corrected in krb5 :

The krb5_gss_process_context_token function in lib/gssapi/krb5/process_context_token.c in the libgssapi_krb5 library in MIT Kerberos 5 (aka krb5) through 1.11.5, 1.12.x through 1.12.2, and 1.13.x before 1.13.1 does not properly maintain security-context handles, which allows remote authenticated users to cause a denial of service (use-after-free and double free, and daemon crash) or possibly execute arbitrary code via crafted GSSAPI traffic, as demonstrated by traffic to kadmind (CVE-2014-5352).

MIT Kerberos 5 (aka krb5) through 1.13.1 incorrectly expects that a krb5_read_message data field is represented as a string ending with a '\0' character, which allows remote attackers to (1) cause a denial of service (NULL pointer dereference) via a zero-byte version string or (2) cause a denial of service (out-of-bounds read) by omitting the '\0' character, related to appl/user_user/server.c and lib/krb5/krb/recvauth.c (CVE-2014-5355).

The auth_gssapi_unwrap_data function in lib/rpc/auth_gssapi_misc.c in MIT Kerberos 5 (aka krb5) through 1.11.5, 1.12.x through 1.12.2, and 1.13.x before 1.13.1 does not properly handle partial XDR deserialization, which allows remote authenticated users to cause a denial of service (use-after-free and double free, and daemon crash) or possibly execute arbitrary code via malformed XDR data, as demonstrated by data sent to kadmind (CVE-2014-9421).

The check_rpcsec_auth function in kadmin/server/kadm_rpc_svc.c in kadmind in MIT Kerberos 5 (aka krb5) through 1.11.5, 1.12.x through 1.12.2, and 1.13.x before 1.13.1 allows remote authenticated users to bypass a kadmin/* authorization check and obtain administrative access by leveraging access to a two-component principal with an initial kadmind substring, as demonstrated by a ka/x principal (CVE-2014-9422).

The svcauth_gss_accept_sec_context function in lib/rpc/svc_auth_gss.c in MIT Kerberos 5 (aka krb5) 1.11.x through 1.11.5, 1.12.x through 1.12.2, and 1.13.x before 1.13.1 transmits uninitialized interposer data to clients, which allows remote attackers to obtain sensitive information from process heap memory by sniffing the network for data in a handle field (CVE-2014-9423).

The updated packages provides a solution for these security issues.

A buffer overflow was found in the KADM5 administration server (kadmind) when it was used with an LDAP back end for the KDC database.
A remote, authenticated attacker could potentially use this flaw to execute arbitrary code on the system running kadmind. (CVE-2014-4345)

A use-after-free flaw was found in the way the MIT Kerberos libgssapi_krb5 library processed valid context deletion tokens. An attacker able to make an application using the GSS-API library (libgssapi) call the gss_process_context_token() function could use this flaw to crash that application. (CVE-2014-5352)

If kadmind were used with an LDAP back end for the KDC database, a remote, authenticated attacker with the permissions to set the password policy could crash kadmind by attempting to use a named ticket policy object as a password policy for a principal.
(CVE-2014-5353)

A double-free flaw was found in the way MIT Kerberos handled invalid External Data Representation (XDR) data. An authenticated user could use this flaw to crash the MIT Kerberos administration server (kadmind), or other applications using Kerberos libraries, using specially crafted XDR packets. (CVE-2014-9421)

It was found that the MIT Kerberos administration server (kadmind) incorrectly accepted certain authentication requests for two-component server principal names. A remote attacker able to acquire a key with a particularly named principal (such as 'kad/x') could use this flaw to impersonate any user to kadmind, and perform administrative actions as that user. (CVE-2014-9422)

An information disclosure flaw was found in the way MIT Kerberos RPCSEC_GSS implementation (libgssrpc) handled certain requests. An attacker could send a specially crafted request to an application using libgssrpc to disclose a limited portion of uninitialized memory used by that application. (CVE-2014-9423)

Two buffer over-read flaws were found in the way MIT Kerberos handled certain requests. A remote, unauthenticated attacker able to inject packets into a client or server application's GSSAPI session could use either of these flaws to crash the application. (CVE-2014-4341, CVE-2014-4342)

A double-free flaw was found in the MIT Kerberos SPNEGO initiators. An attacker able to spoof packets to appear as though they are from an GSSAPI acceptor could use this flaw to crash a client application that uses MIT Kerberos. (CVE-2014-4343)

The krb5 packages have been upgraded to upstream version 1.12, which provides a number of bug fixes and enhancements, including :

  - Added plug-in interfaces for principal-to-username     mapping and verifying authorization to user accounts.

  - When communicating with a KDC over a connected TCP or     HTTPS socket, the client gives the KDC more time to     reply before it transmits the request to another server.

This update also fixes multiple bugs, for example :

  - The Kerberos client library did not recognize certain     exit statuses that the resolver libraries could return     when looking up the addresses of servers configured in     the /etc/krb5.conf file or locating Kerberos servers     using DNS service location. The library could treat     non-fatal return codes as fatal errors. Now, the library     interprets the specific return codes correctly.

In addition, this update adds various enhancements. Among others :

  - Added support for contacting KDCs and kpasswd servers     through HTTPS proxies implementing the Kerberos KDC     Proxy (KKDCP) protocol.

Multiples vulnerabilities have been found in krb5, the MIT implementation of Kerberos :

CVE-2014-5352

Incorrect memory management in the libgssapi_krb5 library might result in denial of service or the execution of arbitrary code.

CVE-2014-9421

Incorrect memory management in kadmind's processing of XDR data might result in denial of service or the execution of arbitrary code.

CVE-2014-9422

Incorrect processing of two-component server principals might result in impersonation attacks.

CVE-2014-9423

An information leak in the libgssrpc library.

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Updated krb5 packages that fix multiple security issues, several bugs, and add various enhancements are now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having Moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

Kerberos is a networked authentication system which allows clients and servers to authenticate to each other with the help of a trusted third party, the Kerberos KDC.

A NULL pointer dereference flaw was found in the MIT Kerberos SPNEGO acceptor for continuation tokens. A remote, unauthenticated attacker could use this flaw to crash a GSSAPI-enabled server application.
(CVE-2014-4344)

A buffer overflow was found in the KADM5 administration server (kadmind) when it was used with an LDAP back end for the KDC database.
A remote, authenticated attacker could potentially use this flaw to execute arbitrary code on the system running kadmind. (CVE-2014-4345)

A use-after-free flaw was found in the way the MIT Kerberos libgssapi_krb5 library processed valid context deletion tokens. An attacker able to make an application using the GSS-API library (libgssapi) call the gss_process_context_token() function could use this flaw to crash that application. (CVE-2014-5352)

If kadmind were used with an LDAP back end for the KDC database, a remote, authenticated attacker with the permissions to set the password policy could crash kadmind by attempting to use a named ticket policy object as a password policy for a principal.
(CVE-2014-5353)

A double-free flaw was found in the way MIT Kerberos handled invalid External Data Representation (XDR) data. An authenticated user could use this flaw to crash the MIT Kerberos administration server (kadmind), or other applications using Kerberos libraries, using specially crafted XDR packets. (CVE-2014-9421)

It was found that the MIT Kerberos administration server (kadmind) incorrectly accepted certain authentication requests for two-component server principal names. A remote attacker able to acquire a key with a particularly named principal (such as 'kad/x') could use this flaw to impersonate any user to kadmind, and perform administrative actions as that user. (CVE-2014-9422)

An information disclosure flaw was found in the way MIT Kerberos RPCSEC_GSS implementation (libgssrpc) handled certain requests. An attacker could send a specially crafted request to an application using libgssrpc to disclose a limited portion of uninitialized memory used by that application. (CVE-2014-9423)

Two buffer over-read flaws were found in the way MIT Kerberos handled certain requests. A remote, unauthenticated attacker able to inject packets into a client or server application's GSSAPI session could use either of these flaws to crash the application. (CVE-2014-4341, CVE-2014-4342)

A double-free flaw was found in the MIT Kerberos SPNEGO initiators. An attacker able to spoof packets to appear as though they are from an GSSAPI acceptor could use this flaw to crash a client application that uses MIT Kerberos. (CVE-2014-4343)

Red Hat would like to thank the MIT Kerberos project for reporting the CVE-2014-5352, CVE-2014-9421, CVE-2014-9422, and CVE-2014-9423 issues.
MIT Kerberos project acknowledges Nico Williams for helping with the analysis of CVE-2014-5352.

The krb5 packages have been upgraded to upstream version 1.12, which provides a number of bug fixes and enhancements, including :

* Added plug-in interfaces for principal-to-username mapping and verifying authorization to user accounts.

* When communicating with a KDC over a connected TCP or HTTPS socket, the client gives the KDC more time to reply before it transmits the request to another server. (BZ#1049709, BZ#1127995)

This update also fixes multiple bugs, for example :

* The Kerberos client library did not recognize certain exit statuses that the resolver libraries could return when looking up the addresses of servers configured in the /etc/krb5.conf file or locating Kerberos servers using DNS service location. The library could treat non-fatal return codes as fatal errors. Now, the library interprets the specific return codes correctly. (BZ#1084068, BZ#1109102)

In addition, this update adds various enhancements. Among others :

* Added support for contacting KDCs and kpasswd servers through HTTPS proxies implementing the Kerberos KDC Proxy (KKDCP) protocol.
(BZ#1109919)

The remote Oracle Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2015-0439 advisory.

    - fix for CVE-2014-5352 (#1179856) 'gss_process_context_token()       incorrectly frees context (MITKRB5-SA-2015-001)'
    - fix for CVE-2014-9421 (#1179857) 'kadmind doubly frees partial       deserialization results (MITKRB5-SA-2015-001)'
    - fix for CVE-2014-9422 (#1179861) 'kadmind incorrectly       validates server principal name (MITKRB5-SA-2015-001)'
    - fix for CVE-2014-9423 (#1179863) 'libgssrpc server applications       leak uninitialized bytes (MITKRB5-SA-2015-001)'
    - fix for CVE-2014-5354 (#1174546) 'krb5: NULL pointer       dereference when using keyless entries'
    - fix for CVE-2014-5353 (#1174543) 'Fix LDAP misused policy       name crash'
    - update to 1.12.2
      - drop patch for RT#7820, fixed in 1.12.2
      - drop patch for #231147, fixed as RT#3277 in 1.12.2
      - drop patch for RT#7818, fixed in 1.12.2
      - drop patch for RT#7836, fixed in 1.12.2
      - drop patch for RT#7858, fixed in 1.12.2
      - drop patch for RT#7924, fixed in 1.12.2
      - drop patch for RT#7926, fixed in 1.12.2
      - drop patches for CVE-2014-4341/CVE-2014-4342, included in 1.12.2
      - drop patch for CVE-2014-4343, included in 1.12.2
      - drop patch for CVE-2014-4344, included in 1.12.2
      - drop patch for CVE-2014-4345, included in 1.12.2
    - incorporate fix for MITKRB5-SA-2014-001 (CVE-2014-4345)
    - gssapi: pull in upstream fix for a possible NULL dereference       in spnego (CVE-2014-4344)
    - gssapi: pull in proposed fix for a double free in initiators (David       Woodhouse, CVE-2014-4343, #1117963)
    - pull in fix for denial of service by injection of malformed GSSAPI tokens       (CVE-2014-4341, CVE-2014-4342, #1116181)

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Security fix for CVE-2014-5352, CVE-2014-9421, CVE-2014-9422, CVE-2014-9423

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Security fix for CVE-2014-5352, CVE-2014-9421, CVE-2014-9422, CVE-2014-9423 Security fix for CVE-2014-5351

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

krb5 has been updated to fix four security issues :

  - gss_process_context_token() incorrectly frees context     (bsc#912002). (CVE-2014-5352)

  - kadmind doubly frees partial deserialization results     (bsc#912002). (CVE-2014-9421)

  - kadmind incorrectly validates server principal name     (bsc#912002). (CVE-2014-9422)

  - libgssrpc server applications leak uninitialized bytes     (bsc#912002) Additionally, these non-security issues     have been fixed :. (CVE-2014-9423)

  - Winbind process hangs indefinitely without DC.
    (bsc#872912)

  - Hanging winbind processes. (bsc#906557)

krb5 was updated to fix five security issues.

These security issues were fixed :

  - CVE-2014-5351: current keys returned when randomizing     the keys for a service principal (bnc#897874) 

  - CVE-2014-5352: An authenticated attacker could cause a     vulnerable application (including kadmind) to crash or     to execute arbitrary code (bnc#912002).

  - CVE-2014-9421: An authenticated attacker could cause     kadmind or other vulnerable server application to crash     or to execute arbitrary code (bnc#912002).

  - CVE-2014-9422: An attacker who possess the key of a     particularly named principal (such as 'kad/root') could     impersonate any user to kadmind and perform     administrative actions as that user (bnc#912002).

  - CVE-2014-9423: An attacker could attempt to glean     sensitive information from the four or eight bytes of     uninitialized data output by kadmind or other libgssrpc     server application. Because MIT krb5 generally sanitizes     memory containing krb5 keys before freeing it, it is     unlikely that kadmind would leak Kerberos key     information, but it is not impossible (bnc#912002).

This non-security issue was fixed :

  - Work around replay cache creation race (bnc#898439).

The remote Ubuntu 14.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-2498-1 advisory.

    It was discovered that Kerberos incorrectly sent old keys in response to a -randkey -keepold request. An     authenticated remote attacker could use this issue to forge tickets by leveraging administrative access.
    This issue only affected Ubuntu 10.04 LTS, Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2014-5351)

    It was discovered that the libgssapi_krb5 library incorrectly processed security context handles. A remote     attacker could use this issue to cause a denial of service, or possibly execute arbitrary code.
    (CVE-2014-5352)

    Patrik Kis discovered that Kerberos incorrectly handled LDAP queries with no results. An authenticated     remote attacker could use this issue to cause the KDC to crash, resulting in a denial of service.
    (CVE-2014-5353)

    It was discovered that Kerberos incorrectly handled creating database entries for a keyless principal when     using LDAP. An authenticated remote attacker could use this issue to cause the KDC to crash, resulting in     a denial of service. (CVE-2014-5354)

    It was discovered that Kerberos incorrectly handled memory when processing XDR data. A remote attacker     could use this issue to cause kadmind to crash, resulting in a denial of service, or possibly execute     arbitrary code. (CVE-2014-9421)

    It was discovered that Kerberos incorrectly handled two-component server principals. A remote attacker     could use this issue to perform impersonation attacks. (CVE-2014-9422)

    It was discovered that the libgssrpc library leaked uninitialized bytes. A remote attacker could use this     issue to possibly obtain sensitive information. (CVE-2014-9423)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

SO-AND-SO reports :

CVE-2014-5352: In the MIT krb5 libgssapi_krb5 library, after gss_process_context_token() is used to process a valid context deletion token, the caller is left with a security context handle containing a dangling pointer. Further uses of this handle will result in use-after-free and double-free memory access violations. libgssrpc server applications such as kadmind are vulnerable as they can be instructed to call gss_process_context_token().

CVE-2014-9421: If the MIT krb5 kadmind daemon receives invalid XDR data from an authenticated user, it may perform use-after-free and double-free memory access violations while cleaning up the partial deserialization results. Other libgssrpc server applications may also be vulnerable if they contain insufficiently defensive XDR functions.

CVE-2014-9422: The MIT krb5 kadmind daemon incorrectly accepts authentications to two-component server principals whose first component is a left substring of 'kadmin' or whose realm is a left prefix of the default realm.

CVE-2014-9423: libgssrpc applications including kadmind output four or eight bytes of uninitialized memory to the network as part of an unused 'handle' field in replies to clients.

Multiple vulnerabilities have been found in krb5, the MIT implementation of Kerberos :

  - CVE-2014-5352     Incorrect memory management in the libgssapi_krb5     library might result in denial of service or the     execution of arbitrary code.

  - CVE-2014-9421     Incorrect memory management in kadmind's processing of     XDR data might result in denial of service or the     execution of arbitrary code.

  - CVE-2014-9422     Incorrect processing of two-component server principals     might result in impersonation attacks.

  - CVE-2014-9423     An information leak in the libgssrpc library.

ID	Name	Product	Family	Severity
83874	AIX NAS Advisory : nas_advisory3.asc	Nessus	AIX Local Security Checks	high
83683	SUSE SLED12 / SLES12 Security Update : krb5 (SUSE-SU-2015:0290-2)	Nessus	SuSE Local Security Checks	high
83682	SUSE SLES12 Security Update : krb5 (SUSE-SU-2015:0290-1)	Nessus	SuSE Local Security Checks	high
82322	Mandriva Linux Security Advisory : krb5 (MDVSA-2015:069)	Nessus	Mandriva Local Security Checks	high
82255	Scientific Linux Security Update : krb5 on SL7.x x86_64 (20150305)	Nessus	Scientific Linux Local Security Checks	high
82129	Debian DLA-146-1 : krb5 security update	Nessus	Debian Local Security Checks	high
81896	CentOS 7 : krb5 (CESA-2015:0439)	Nessus	CentOS Local Security Checks	high
81805	Oracle Linux 7 : krb5 (ELSA-2015-0439)	Nessus	Oracle Linux Local Security Checks	critical
81796	Fedora 21 : krb5-1.12.2-14.fc21 (2015-2347)	Nessus	Fedora Local Security Checks	high
81705	Fedora 20 : krb5-1.11.5-18.fc20 (2015-2382)	Nessus	Fedora Local Security Checks	high
81637	RHEL 7 : krb5 (RHSA-2015:0439)	Nessus	Red Hat Local Security Checks	high
81312	SuSE 11.3 Security Update : krb5 (SAT Patch Number 10282)	Nessus	SuSE Local Security Checks	high
81304	openSUSE Security Update : krb5 (openSUSE-2015-128)	Nessus	SuSE Local Security Checks	high
81297	Ubuntu 14.04 LTS : Kerberos vulnerabilities (USN-2498-1)	Nessus	Ubuntu Local Security Checks	medium
81175	FreeBSD : krb5 -- Vulnerabilities in kadmind, libgssrpc, gss_process_context_token VU#540092 (24ce5597-acab-11e4-a847-206a8a720317)	Nessus	FreeBSD Local Security Checks	high
81150	Debian DSA-3153-1 : krb5 - security update	Nessus	Debian Local Security Checks	high

Detections

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CVE-2014-9423

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