Security Bulletin: Vulnerabilities in MIT Kerberos 5 (krb5) affect PowerKVM (CVE-2014-5355, CVE-2015-2694)

Summary

PowerKVM is affected by two vulnerabilities in MIT Kerberos 5 (krb5). These vulnerabilities are now fixed.

Vulnerability Details

CVEID: CVE-2014-5355**
DESCRIPTION:** MIT Kerberos is vulnerable to a denial of service, caused by a NULL pointer dereference in the krb5_recvauth function. By sending a non-null-terminated version string, a remote attacker could exploit this vulnerability to cause the service to crash.
CVSS Base Score: 5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/100972 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:N/I:N/A:P)

CVEID: CVE-2015-2694**
DESCRIPTION:** MIT Kerberos 5 (krb5) could allow a remote attacker to bypass security restrictions, caused by an error in kdcpreauth modules. By sending a specially-crafted request, an attacker could exploit this vulnerability to bypass access restrictions.
CVSS Base Score: 6.4
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/105375 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:P/I:P/A:N)

Affected Products and Versions

PowerKVM 2.1 and PowerKVM 3.1

Remediation/Fixes

Customers can update PowerKVM systems by using “yum update”.

Fix images are made available via Fix Central. For version 3.1, see https://ibm.biz/BdHggw for 3.1 service build 3 or later.

For version 2.1, the fix is made available via Fix Central (https://ibm.biz/BdEnT8) in 2.1.1 Build 65.6 and all later 2.1.1 SP3 service builds and 2.1.1 service packs. Customers running v2.1 are, in any case, encouraged to upgrade to v3.1.

For v2.1 systems currently running fix levels of PowerKVM prior to 2.1.1, please see <http://download4.boulder.ibm.com/sar/CMA/OSA/05e4c/0/README&gt; for prerequisite fixes and instructions.

Workarounds and Mitigations

v2.1 customers can work around the problem by upgrading to the fixed release of v3.1