The DNS resolution functionality in the CIFS implementation in the Linux kernel before 2.6.35, when CONFIG_CIFS_DFS_UPCALL is enabled, relies on a users keyring for the dns_resolver upcall in the cifs.upcall userspace helper, which allows local users to spoof the results of DNS queries and perform arbitrary CIFS mounts via vectors involving an add_key call, related to a cache stuffing issue and MS-DFS referrals.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Linux_kernel | Linux | * | 2.6.35 (excluding) |
| Red Hat Enterprise Linux 5 | RedHat | kernel-0:2.6.18-194.11.1.el5 | * |
| Linux | Ubuntu | jaunty | * |
| Linux | Ubuntu | karmic | * |
| Linux | Ubuntu | lucid | * |
| Linux | Ubuntu | upstream | * |
| Linux-ec2 | Ubuntu | karmic | * |
| Linux-ec2 | Ubuntu | lucid | * |
| Linux-ec2 | Ubuntu | maverick | * |
| Linux-fsl-imx51 | Ubuntu | karmic | * |
| Linux-fsl-imx51 | Ubuntu | lucid | * |
| Linux-lts-backport-maverick | Ubuntu | lucid | * |