Active Exploitation of Vulnerability in BIND

Number: AL15-011
Date: 31 July 2015


The purpose of this alert is to bring attention to recently active exploitation of a recently disclosed vulnerability in BIND.


CCIRC is aware of attacks exploiting a recently patched vulnerability in BIND.  As a result, CCIRC would like to raise awareness concerning this potentially serious vulnerability. Malicious actors can exploit this vulnerability against authoritative and recursive domain name servers, which forces the BIND process to exit, causing a denial of service.

The affected versions of BIND include: 9.1.0 to 9.8.x, 9.9.0 to 9.9.7-P1 & 9.10.0 to 9.10.2-P2

CVE Reference: CVE-2015-5477

Suggested action

Due to the elevated risk that this vulnerability presents, CCIRC recommends that system administrators test and deploy vendor-released updates to affected applications accordingly. CCIRC recommends that priority is given to these patches.


ISC: About CVE-2015-5477

ISC: CVE-2015-5477: An error in handling TKEY queries can cause named to exit with a REQUIRE assertion failure

Arstechnica: Major flaw could let lone-wolf hacker bring down huge swaths of Internet

Note to Readers

In support of Public Safety's mission to build a safe and resilient Canada, CCIRC's mandate is to help ensure the security and resilience of the vital non-federal government cyber systems that underpin Canada's national security, public safety and economic prosperity. As Canada's computer security incident response team, CCIRC is Canada's national coordination centre for the prevention and mitigation of, preparedness for, response to, and recovery from cyber incidents on non-federal government systems. It does this by providing authoritative advice and support, and coordinating information sharing and incident response.

Please note, CCIRC PGP key has recently been updated.

For general information, please contact Public Safety Canada's Public Affairs division at:

Telephone: 613-944-4875 or 1-800-830-3118
Fax: 613-998-9589

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