Netkit FTP Server: Privilege escalation
Gentoo Linux Security Advisory
||GLSA 200611-05 / ftpd
||November 10, 2006
||December 30, 2007: 02
All supported architectures
An incorrect seteuid() call could allow an FTP user to access some files or
directories that would normally be inaccessible.
net-ftp/netkit-ftpd is the Linux Netkit FTP server with optional SSL support.
Paul Szabo reported that an incorrect seteuid() call after the chdir()
function can allow an attacker to access a normally forbidden
directory, in some very particular circumstances, for example when the
NFS-hosted targetted directory is not reachable by the client-side root
user. Additionally, some potentially exploitable unchecked setuid()
calls were also fixed.
A local attacker might craft his home directory to gain access through
ftpd to normally forbidden directories like /root, possibly with
writing permissions if seteuid() fails and if the ftpd configuration
allows that. The unchecked setuid() calls could also lead to a root FTP
login, depending on the FTP server configuration.
There is no known workaround at this time.
All Netkit FTP Server users should upgrade to the latest version:
Code Listing 3.1: Resolution
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-ftp/netkit-ftpd-0.17-r4"