mount-cifs is the cifs filesystem mount helper split from Samba.
Multiple vulnerabilities have been discovered in mount-cifs. Please review the CVE identifiers referenced below for details.
The vulnerabilities allow local users to cause a denial of service (mtab corruption) via a crafted string. Also, local users could mount a CIFS share on an arbitrary mountpoint, and gain privileges via a symlink attack on the mountpoint directory file.
There is no known workaround at this time.
Gentoo has discontinued support for mount-cifs. We recommend that users unmerge mount-cifs:
# emerge --unmerge "net-fs/mount-cifs"