It was found that libgssapi and libgssglue GSSAPI interface exporting libraries did not properly sanitize content of user-provided configuration file, determining which GSS mechanisms and their definitions will be loaded during library initialization. A local attacker, allowed to mount a network file system (NFS) share could use this flaw to execute arbitrary code with the privileges of the the privileged system user (root).
Links to patches, applied by SUSE Linux distribution (couldn't find their
related source code form though):
This issue affects the versions of the libgssapi package, as shipped with Red Hat Enterprise Linux 4 and 5.
This issue affects the version of the libgssglue package, as shipped with Red Hat Enterprise Linux 6.
This issue affects the versions of the libgssapi package, as shipped with Fedora release of 14 and 15.
This issue affects the versions of the libgssglue package, as shipped with Fedora release of 14 and 15.
Please schedule an update.
Created libgssglue tracking bugs for this issue
Affects: fedora-all [bug 724009]
Created libgssapi tracking bugs for this issue
Affects: fedora-all [bug 724008]
Request for CVE and plaintext version of the patches:
The CVE identifier of CVE-2011-2709 has been assigned to this issue:
Patch that was used by SUSE:
It checks for uid != euid to handle setuid mount.nfs use case. Adding gid != egid check to cover possible setgid use case (even though none seem to be known at the moment) seems like a reasonable extension to SUSE's fix.
Upstream fixed this in libgssglue-0.4:
Although the library is affected by this vulnerability, we are not aware of an application shipping as part of RHEL that would offer a suitable attack vector to actually exploit this vulnerability in a way that would cross security boundaries.
It can't be ruled out completely that third party applications offer a suitable attack vector (e.g. a suid/sgid binary that triggers the affected initialization routines of the library). However, we are currently not aware of such an application.
Thus, this issue has been rated as having a low security impact, even though the theoretical CVSSv2 score is quite high. It's still being tracked and a future update may address this issue.
Red Hat Product Security has rated this issue as having Low security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.