Scientific Linux Security Update : openafs on SL5.x SL6.x i386/x86_64
Medium Nessus Plugin ID 65021
SynopsisThe remote Scientific Linux host is missing one or more security updates.
DescriptionBy carefully crafting an ACL entry an attacker may overflow fixed length buffers within the OpenAFS fileserver, crashing the fileserver, and potentially permitting the execution of arbitrary code. To perform the exploit, the attacker must already have permissions to create ACLs on the fileserver in question. Once such an ACL is present on a fileserver, client utilities such as 'fs' which manipulate ACLs, may be crashed when they attempt to read or modify the ACL.(CVE-2013-1794)
The ptserver accepts a list of unbounded size from the IdToName RPC.
The length of this list is then used to determine the size of a number of other internal data structures. If the length is sufficiently large then we may hit an integer overflow when calculating the size to pass to malloc, and allocate data structures of insufficient length, allowing heap memory to be overwritten. This may allow an unauthenticated attacker to crash an OpenAFS ptserver. (CVE-2013-1795)
Scientific Linux 5 users must also update to at least kernel-2.6.18-308.20.1.el5 to receive a compatible kernel module.
Scientific Linux 6 users must also update to at least kernel-2.6.32-279.el6 to avoid issues with system stability. Any 32-bit SL6 system should be aware of possible problems with the afs cache when switching from kernels prior to kernel-2.6.32-279.el6.
Purging your OpenAFS cache seems to resolve this issue.
After installing the update, OpenAFS services must be restarted for the changes to take effect.
SolutionUpdate the affected packages.