SB2017072303 - Input validation error in tor.eff Tor

Description

This security bulletin contains information about 1 security vulnerability.

1) Input validation error (CVE-ID: CVE-2017-11565)

The vulnerability allows a remote non-authenticated attacker to manipulate data.

debian/tor.init in the Debian tor_0.2.9.11-1~deb9u1 package for Tor was designed to execute aa-exec from the standard system pathname if the apparmor package is installed, but implements this incorrectly (with a wrong assumption that the specific pathname would remain the same forever), which allows attackers to bypass intended AppArmor restrictions by leveraging the silent loss of this protection mechanism. NOTE: this does not affect systems, such as default Debian stretch installations, on which Tor startup relies on a systemd unit file (instead of this tor.init script).

Remediation

Install update from vendor's website.

References

• http://www.securityfocus.com/bid/99933
• https://bugs.debian.org/869153