The remote Debian host is missing a security-related update.
Multiple security vulnerabilities were discovered in the Tomcat servlet and JSP engine, as well as in its Debian-specific maintainer scripts. Those flaws allowed for privilege escalation, information disclosure, and remote code execution. As part of this update, several regressions stemming from incomplete fixes for previous vulnerabilities were also fixed.
Upgrade the tomcat7 packages. For the stable distribution (jessie), these problems have been fixed in version 7.0.56-3+deb8u6.