A firebird2.5 security update has been released for Debian GNU/Linux 8 LTS to address an issue.

Package : firebird2.5
Version : 2.5.3.26778.ds4-5+deb8u2
CVE ID : CVE-2017-11509

An issues has been found in firebird2.5, an RDBMS based on InterBase 6.0.
As UDFs can be used for a remote authenticated code execution (as user
firebird), UDFs have been disabled in the default configuration
which will be used for new installations (there is no change for existing
configurations, which must be done manually).

For Debian 8 "Jessie", this problem has been fixed in version
2.5.3.26778.ds4-5+deb8u2.

We recommend that you upgrade your firebird2.5 packages.

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at:   https://wiki.debian.org/LTS