--- /dev/null
+## PowerDNS Security Advisory 2016-01: Crafted queries can cause unexpected backend load
+
+* CVE: CVE-2016-5426, CVE-2016-5427
+* Date: 9th of September 2016
+* Credit: Florian Heinz and Martin Kluge
+* Affects: PowerDNS Authoritative Server up to and including 3.4.9
+* Not affected: PowerDNS Authoritative Server 3.4.10, 4.x
+* Severity: Medium
+* Impact: Degraded service or Denial of service
+* Exploit: This problem can be triggered by sending specially crafted query packets
+* Risk of system compromise: No
+* Solution: Upgrade to a non-affected version
+* Workaround: Run dnsdist with the rules provided below in front of potentially affected servers, or dimension the backend capacity so that it can handle the increased load.
+
+Two issues have been found in PowerDNS Authoritative Server allowing a remote, unauthenticated attacker to cause an abnormal load on the PowerDNS backend by sending crafted DNS queries, which might result in a partial denial of service if the backend becomes overloaded. SQL backends for example are particularly vulnerable to this kind of unexpected load if they have not been dimensioned for it.
+The first issue is based on the fact that PowerDNS Authoritative Server accepts queries with a qname's length larger than 255 bytes. This issue has been assigned CVE-2016-5426.
+The second issue is based on the fact that PowerDNS Authoritative Server does not properly handle dot inside labels. This issue has been assigned CVE-2016-5427.
+Both issues have been addressed by this [commit](https://github.com/PowerDNS/pdns/commit/881b5b03a590198d03008e4200dd00cc537712f3).
+
+PowerDNS Authoritative Server up to and including 3.4.9 is affected. No other versions are affected. The PowerDNS Recursor is not affected.
+
+dnsdist can be used to block crafted queries, using QNameWireLengthRule() to block queries with a qname larger than 255 bytes and QNameLabelsCountRule() to block queries with a very large amount of labels. Please note that restricting the number of labels in a query might lead to unexpected issues, especially with DNSSEC-enabled domains.
+
+We'd like to thank Florian Heinz and Martin Kluge for finding and subsequently reporting this issue.
-@ 86400 IN SOA pdns-public-ns1.powerdns.com. pieter\.lexis.powerdns.com. 2016090502 10800 3600 604800 10800
+@ 86400 IN SOA pdns-public-ns1.powerdns.com. pieter\.lexis.powerdns.com. 2016090907 10800 3600 604800 10800
@ 3600 IN NS pdns-public-ns1.powerdns.com.
@ 3600 IN NS pdns-public-ns2.powerdns.com.
; Auth
auth-3.4.4.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-01/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-03/"
auth-3.4.5.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-03/"
auth-3.4.6.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-03/"
-auth-3.4.7.security-status 60 IN TXT "1 OK"
-auth-3.4.8.security-status 60 IN TXT "1 OK"
-auth-3.4.9.security-status 60 IN TXT "1 OK"
+auth-3.4.7.security-status 60 IN TXT "2 Upgrade recommended, see https://doc.powerdns.com/md/security/powerdns-advisory-2016-01/"
+auth-3.4.8.security-status 60 IN TXT "2 Upgrade recommended, see https://doc.powerdns.com/md/security/powerdns-advisory-2016-01/"
+auth-3.4.9.security-status 60 IN TXT "2 Upgrade recommended, see https://doc.powerdns.com/md/security/powerdns-advisory-2016-01/"
auth-3.4.10.security-status 60 IN TXT "1 OK"
auth-4.0.0-alpha1.security-status 60 IN TXT "2 Unsupported pre-release (no known vulnerabilities). Please upgrade to final, see https://blog.powerdns.com/2016/07/11/powerdns-authoritative-server-4-0-0-released/"
auth-3.4.4-2.debian.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-01/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-03/"
auth-3.4.5-1.debian.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-03/"
auth-3.4.6-1.debian.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-03/"
-auth-3.4.7-1.debian.security-status 60 IN TXT "1 OK"
+auth-3.4.7-1.debian.security-status 60 IN TXT "2 Upgrade recommended, see https://doc.powerdns.com/md/security/powerdns-advisory-2016-01/"
auth-3.4.1-3_bpo70_1.debian.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-01/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/"
auth-3.4.1-4_bpo70_1.debian.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-01/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/"
auth-3.4.4-2_bpo7_1.debian.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-01/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-03/"
auth-3.4.5-1_bpo7_1.debian.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-03/"
auth-3.4.6-1_bpo7_1.debian.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-03/"
-auth-3.4.7-1_bpo7_1.debian.security-status 60 IN TXT "1 OK"
+auth-3.4.7-1_bpo7_1.debian.security-status 60 IN TXT "2 Upgrade recommended, see https://doc.powerdns.com/md/security/powerdns-advisory-2016-01/"
auth-3.4.1-4_deb8u1.debian.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-01/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/"
auth-3.4.1-4_deb8u2.debian.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/"
-auth-3.4.1-4_deb8u3.debian.security-status 60 IN TXT "1 OK"
-auth-3.4.1-4_deb8u4.debian.security-status 60 IN TXT "1 OK"
-auth-3.4.1-4_deb8u5.debian.security-status 60 IN TXT "1 OK"
+auth-3.4.1-4_deb8u3.debian.security-status 60 IN TXT "2 Upgrade recommended, see https://doc.powerdns.com/md/security/powerdns-advisory-2016-01/"
+auth-3.4.1-4_deb8u4.debian.security-status 60 IN TXT "2 Upgrade recommended, see https://doc.powerdns.com/md/security/powerdns-advisory-2016-01/"
+auth-3.4.1-4_deb8u5.debian.security-status 60 IN TXT "2 Upgrade recommended, see https://doc.powerdns.com/md/security/powerdns-advisory-2016-01/"
auth-3.4.1-4_deb8u6.debian.security-status 60 IN TXT "1 OK"
auth-3.4.4-2_bpo8_1.debian.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-01/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-03/"
auth-3.4.5-1_bpo8_1.debian.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-03/"
auth-3.4.6-1_bpo8_1.debian.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-03/"
-auth-3.4.7-1_bpo8_1.debian.security-status 60 IN TXT "1 OK"
+auth-3.4.7-1_bpo8_1.debian.security-status 60 IN TXT "2 Upgrade recommended, see https://doc.powerdns.com/md/security/powerdns-advisory-2016-01/"
auth-4.0.0_alpha1-1.debian.security-status 60 IN TXT "2 Unsupported pre-release (no known vulnerabilities). Please upgrade to final, see https://blog.powerdns.com/2016/07/11/powerdns-authoritative-server-4-0-0-released/"
auth-4.0.0_alpha1-2.debian.security-status 60 IN TXT "2 Unsupported pre-release (no known vulnerabilities). Please upgrade to final, see https://blog.powerdns.com/2016/07/11/powerdns-authoritative-server-4-0-0-released/"
auth-3.4.1-4.ubuntu.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-01/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/"
auth-3.4.5-1.ubuntu.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-02/ and https://doc.powerdns.com/md/security/powerdns-advisory-2015-03"
auth-3.4.6-1.ubuntu.security-status 60 IN TXT "3 Upgrade now, see https://doc.powerdns.com/md/security/powerdns-advisory-2015-03/"
-auth-3.4.7-1.ubuntu.security-status 60 IN TXT "1 OK"
+auth-3.4.7-1.ubuntu.security-status 60 IN TXT "2 Upgrade recommended, see https://doc.powerdns.com/md/security/powerdns-advisory-2016-01/"
auth-4.0.0_alpha1-1.ubuntu.security-status 60 IN TXT "2 Unsupported pre-release (no known vulnerabilities). Please upgrade to final, see https://blog.powerdns.com/2016/07/11/powerdns-authoritative-server-4-0-0-released/"
auth-4.0.0_alpha2-1.ubuntu.security-status 60 IN TXT "2 Unsupported pre-release (no known vulnerabilities). Please upgrade to final, see https://blog.powerdns.com/2016/07/11/powerdns-authoritative-server-4-0-0-released/"