Vulnerabilities in the MIT Kerberos libgssrpc library may allow an attacker to cause a denial of service or potentially execute arbitrary code.
The MIT krb5 Kerberos implementation includes a GSS RPC library used in the Kerberos administration server (kadmind). Two flaws exist in the libgssprc library that can cause an array overrun if too many file descriptors are opened. These flaws result in a vulnerability that could allow memory corruption in the kadmind server.
MIT notes that in software versions 1.4 and later, this flaw can only be exploited in configurations that allow large numbers of open file descriptors in a process. In software versions before 1.3, a similar flaw can be exploited in similar circumstances but is further limited to platforms that do not define certain macros in certain C system header files.
An unauthenticated remote attacker can cause memory corruption in the libgssrpc library used by kadmind. kadmind will crash, thereby resulting in a denial of service. MIT notes that it is at least theoretically possible for such corruption to result in database corruption or arbitrary code execution.
Upgrade or apply a patch from the vendor
Thanks to Ken Raeburn of the MIT Kerberos Team for reporting this vulnerability. MIT credits Jeff Altman of Secure Endpoints with discovering and reporting this issue in software version 1.6.3 and the Red Hat Security Response Team for reporting relevant information about older versions of the software.
This document was written by Chad R Dougherty.