Debian 9: DSA-27671-1 Critical: Proftpd DoS Input Issue

Kingcope discovered that the mod_sftp and mod_sftp_pam modules of
proftpd, a powerful modular FTP/SFTP/FTPS server, are not properly
validating input, before making pool allocations. An attacker can
use this flaw to conduct denial of service attacks against the system
running proftpd (resource exhaustion).

For the oldstable distribution (squeeze), this problem has been fixed in
version 1.3.3a-6squeeze7.

For the stable distribution (wheezy), this problem has been fixed in
version 1.3.4a-5+deb7u1.

For the testing (jessie) unstable (sid) distributions, this problem will
be fixed soon.

We recommend that you upgrade your proftpd-dfsg packages.

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: http://www.debian.org/security/