Category: Uncategorized

PowerDNS Recursor 4.4.5 and 4.5.5 Released

We are proud to announce the release of PowerDNS Recursor 4.4.5. and 4.5.5.

Both releases contain an improvement to work around broken authoritative servers sending replies without the “authoritative answer” (AA) bit set.

The 4.5.5 release contains a fix to an issue where an insecure domain with signatures records could be marked as bogus due to a missed zone cut and a fix to the aggressive NSEC(3) cache handling of denials of DS records.

Please refer to the change logs for the 4.4.4 and 4.5.5 releases for additional details.

Please send us all feedback and issues you might have via the mailing list, or in case of a bug, via GitHub.

The tarballs (4.4.5, 4.5.5) and signatures (4.4.5, 4.5.5) are available from our download server and packages for several distributions are available from our repository.

The 4.2.x release is EOL and the 4.3.x and 4.4.x releases are in critical fixes only mode. Consult the EOL policy for more details.

We would also like to announce that starting with the 4.5 release we will stop supporting systems using 32-bit time. This includes 32-bit Linux platforms like arm6, arm7, and i386.

We are grateful to the PowerDNS community for the reporting of bugs, issues, feature requests, and especially to the submitters of fixes and implementations of features.

security advisory 2021-01 for PowerDNS Authoritative Server 4.5.0

Hello,

today we have released PowerDNS Authoritative Server 4.5.1, fixing a remotely triggered crash present in version 4.5.0. No other versions are affected.

Tarballs and signatures are available at https://downloads.powerdns.com/releases/, and a single patch is available at https://downloads.powerdns.com/patches/2021-01/. However, 4.5.1 contains no other changes.

Please find the full text of the advisory below.

PowerDNS Security Advisory 2021-01: Specific query crashes Authoritative Server

  • CVE: CVE-2021-36754
  • Date: July 26th, 2021
  • Affects: PowerDNS Authoritative version 4.5.0
  • Not affected: 4.4.x and below, 4.5.1
  • Severity: High
  • Impact: Denial of service
  • Exploit: This problem can be triggered via a specific query packet
  • Risk of system compromise: None
  • Solution: Upgrade to 4.5.1, or filter queries in dnsdist

PowerDNS Authoritative Server 4.5.0 (and the alpha/beta/rc1/rc2 prereleases that came before it) will crash with an uncaught out of bounds exception if it receives a query with QTYPE 65535. The offending code was not present in earlier versions, and they are not affected.

Users that cannot upgrade immediately, but do have dnsdist in place, can use dnsdist to filter such queries before they do harm, with something like addAction(QTypeRule(65535), RCodeAction(DNSRCode.REFUSED)).

When the PowerDNS Authoritative Server is run inside a supervisor like supervisord or systemd, an uncaught exception crash will lead to an automatic restart, limiting the impact to a somewhat degraded service.

We would like to thank Reinier Schoof and Robin Geuze of TransIP for noticing crashes in production, immediately letting us know, and helping us figure out what was happening.

PowerDNS Authoritative Server 4.5.0

Hello!

PowerDNS Authoritative Server 4.5.0 was released today.

Version 4.5.0 mostly brings small improvements and fixes, but there are two notable new features:

  • The ‘zone cache’, which allows PowerDNS to keep a list of zones in memory, updated periodically. With this cache, PowerDNS can avoid hitting the database with queries for unknown domains. In some setups, and some attack scenarios, this can make a serious performance difference. Users of backends with dynamically generated zones may want to disable this or at least read the upgrade notes extremely carefully. Many thanks to Chris Hofstaedtler for implementing this. This work by Chris was supported by RcodeZero DNS.

  • Priority ordering in the AXFR queue in PowerDNS running as a secondary. Some users with a lot of domains (>100k) sometimes found real changes waiting behind signature refreshes on Thursdays. With the new ordering, those real changes can ‘skip the line’ and get deployed on your secondaries faster. Many thanks to Robin Geuze of TransIP for implementing this.

Since 4.5.0-beta1, the zone cache is enabled by default.

A full list of changes can be found in the changelog.

Please make sure to read the Upgrade Notes before upgrading.

With version 4.5.0, support for platforms with a time_t type smaller than 64 bits is dropped. This means that we do not build packages for Raspberry Pi OS.

The tarball (signature) is available at downloads.powerdns.com. Packages for various distributions are available from repo.powerdns.com.

Please send us all feedback and issues you might have via the mailing list, or in case of a bug, via GitHub.

PowerDNS Authoritative Server 4.5.0-RC2

Hello!

Today we released the second, and hopefully last, Release Candidate for Authoritative Server version 4.5.0. Please try it!

Version 4.5.0 mostly brings small improvements and fixes, but there are two notable new features:

  • The ‘zone cache’, which allows PowerDNS to keep a list of zones in memory, updated periodically. With this cache, PowerDNS can avoid hitting the database with queries for unknown domains. In some setups, and some attack scenarios, this can make a serious performance difference. Many thanks to Chris Hofstaedtler for implementing this.
  • Priority ordering in the AXFR queue in PowerDNS running as a secondary. Some users with a lot of domains (>100k) sometimes found real changes waiting behind signature refreshes on Thursdays. With the new ordering, those real changes can ‘skip the line’ and get deployed on your secondaries faster. Many thanks to Robin Geuze for implementing this.

Since 4.5.0-beta1, the zone cache is enabled by default.

A full list of changes can be found in the changelog.

Please make sure to read the Upgrade Notes before upgrading.

With version 4.5.0, support for platforms with a time_t type smaller than 64 bits is dropped. This means that we do not build packages for Raspberry Pi OS.

The tarball (signature) is available at downloads.powerdns.com. Packages for various distributions are available from repo.powerdns.com.

Please send us all feedback and issues you might have via the mailing list, or in case of a bug, via GitHub.

PowerDNS Recursor 4.5.4 Released

We are proud to announce the release of PowerDNS Recursor 4.5.4. This release contains a fix to an issue where the answer to a non-existent DS query was missing a SOA record. In particular this can be a problem if PowerDNS Recursor is used as a forwarding target by a validating client.

Due to an issue with the build system PowerDNS Recursor 4.5.3 was never released publicly.

Please refer to the change log for additional details.

Please send us all feedback and issues you might have via the mailing list, or in case of a bug, via GitHub.

The tarball and signature are available from our download server and packages for several distributions are available from our repository.

With the earlier 4.5.1 release, the 4.2.x releases will be EOL and the 4.3.x and 4.4.x releases will go into critical fixes only mode. Consult the EOL policy for more details.

We would also like to announce that with this release we will stop supporting systems using 32-bit time. This includes 32-bit Linux platforms like arm6, arm7, and i386.

We are grateful to the PowerDNS community for the reporting of bugs, issues, feature requests, and especially to the submitters of fixes and implementations of features.

PowerDNS Authoritative Server 4.5.0-RC1

Hello!

Today we released the first Release Candidate for Authoritative Server version 4.5.0. Please try it!

Version 4.5.0 mostly brings small improvements and fixes, but there is one notable new feature: the zone cache.

The zone cache allows PowerDNS to keep a list of zones in memory, updated periodically. With this cache, PowerDNS can avoid hitting the database with queries for unknown domains. In some setups, and some attack scenarios, this can make a serious performance difference.

Since 4.5.0-beta1, the zone cache is enabled by default.

A full list of changes can be found in the changelog.

Please make sure to read the Upgrade Notes before upgrading.

With version 4.5.0, support for platforms with a time_t type smaller than 64 bits is dropped. This means that we do not build packages for Raspberry Pi OS.

The tarball (signature) is available at downloads.powerdns.com. Packages for various distributions are available from repo.powerdns.com.

Please send us all feedback and issues you might have via the mailing list, or in case of a bug, via GitHub.

PowerDNS Authoritative Server 4.5.0-beta1

Hello!

Today we released the first Beta version for Authoritative Server version 4.5.0.

Version 4.5.0 mostly brings small improvements and fixes, but there is one notable new feature: the zone cache.

The zone cache allows PowerDNS to keep a list of zones in memory, updated periodically. With this cache, PowerDNS can avoid hitting the database with queries for unknown domains. In some setups, and some attack scenarios, this can make a serious performance difference.

In beta1, the zone cache is enabled by default.

A full list of changes can be found in the changelog.

Please make sure to read the Upgrade Notes before upgrading.

With version 4.5.0, support for platforms with a time_t type smaller than 64 bits is dropped. This means that we do not build packages for Raspberry Pi OS.

The tarball (signature) is available at downloads.powerdns.com. Packages for various distributions are available from repo.powerdns.com.

Please send us all feedback and issues you might have via the mailing list, or in case of a bug, via GitHub.

PowerDNS Recursor 4.4.4 and 4.5.2 Released

We are proud to announce the release of PowerDNS Recursor 4.4.4. and 4.5.2. Both releases contain mostly smaller bug fixes. For the 4.5.2 release the default value of nsec3-max-iterations has  been lowered to 150, in accordance with new guidelines and in coordination with other vendors. Furthermore, an issue affecting the “refresh almost expired” function has been fixed.

Please refer to the change logs for the 4.4.4 and 4.5.2 release for additional details.

Please send us all feedback and issues you might have via the mailing list, or in case of a bug, via GitHub.

The tarballs (4.4.4, 4.5.2) and signatures (4.4.4, 4.5.2) are available from our download server and packages for several distributions are available from our repository.

With the previous 4.5.1 release, the 4.2.x releases will be EOL and the 4.3.x and 4.4.x releases will go into critical fixes only mode. Consult the EOL policy for more details.

We would also like to announce that with this release we will stop supporting systems using 32-bit time. This includes 32-bit Linux platforms like arm6, arm7, and i386.

We are grateful to the PowerDNS community for the reporting of bugs, issues, feature requests, and especially to the submitters of fixes and implementations of features.

PowerDNS Authoritative Server 4.5.0-alpha1

Hello!

Today we released the first Alpha version for Authoritative Server version 4.5.0.

Version 4.5.0 mostly brings small improvements and fixes, but there is one notable new feature: the zone cache.

The zone cache allows PowerDNS to keep a list of zones in memory, updated periodically. With this cache, PowerDNS can avoid hitting the database with queries for unknown domains. In some setups, and some attack scenarios, this can make a serious performance difference.

A full list of changes can be found in the changelog.

Please make sure to read the Upgrade Notes before upgrading.

With version 4.5.0, support for platforms with a time_t type smaller than 64 bits is dropped. This means that we do not build packages for Raspberry Pi OS.

The tarball (signature) is available at downloads.powerdns.com. Packages for various distributions are available from repo.powerdns.com.

Please send us all feedback and issues you might have via the mailing list, or in case of a bug, via GitHub.

PowerDNS Recursor 4.5.1 Released

We are proud to announce the release of PowerDNS Recursor 4.5.1. Compared to the release candidate, this release contains two bug fixes. Note that 4.5.0 was never released publicly, since an issue was found during QA.

Compared to the previous major (4.4) release of PowerDNS Recursor, this release contains a rewrite of the way zone cuts are determined, reducing the number of outgoing queries by up to 17% when doing DNSSEC validation while reducing the CPU usage more than 20% .

Another notable feature is the implementation of EDNS0 padding (RFC 7830) for answers sent to clients.

This 4.5.1 release includes an important addition: the implementation of RFC 8198: Aggressive use of DNSSEC-Validated Cache. This enables the Recursor to answer queries for non-existing names with less effort in many cases. This feature uses both NSEC and NSEC3 records. Additionally the DNSSEC default mode is now “process”, while it was “process-no-validate” before. This means that clients asking for it will get DNSSEC validated answers by default.

We also added a cache of non-resolving nameservers. This enhances performance when the Recursor encounters domains that list nameservers that do not resolve and further mitigates the TsuNAME vulnerability.

This release also features a re-worked negative cache that is shared between threads, allowing more efficient use of the cache and reduced memory consumption.

Support for Extended DNS Errors (RFC 8914) has been added. These can be enabled by setting the extended-resolution-errors setting to ‘yes’, this will send DNSSEC and resolution related errors to clients. Extended Errors are also hooked up to the Lua scripting engine, allowing fine-grained setting of both the error code and extra information in the response.

A “refresh almost expired records” (also called “refetch”) mechanism has been introduced to keep the record cache warm. In short, if a query comes in and the cached record’s TTL is almost expired (within N percent of its original value) the cached record is served to the client and the record queried for in the background, ensuring that new queries for that record are fresh and served from the cache.

Other new features and improvements are:

  • The complete protobuf and dnstap logging code has been rewritten to have much smaller performance impact.
  • We have introduced non-offensive synonyms for words used in settings. See the upgrade guide.
  • The default minimum TTL override has been changed from 0 to 1.
  • The spoof-nearmiss-max setting‘s default has been changed to 1. This has the consequence that the Recursor will switch to do TCP queries to authoritative nameservers sooner as an effective measure against many spoofing attacks.
  • Incoming queries over TCP now also use the packet cache, providing another performance increase.
  • File written to by the rec_control command are new opened by the command itself. It is also possible to write the content to the standard output stream by using a hyphen as file name.
  • TCP FastOpen (RFC 7413) support for outgoing TCP connections to authoritative servers and forwarders.

Please refer to the changelog for additional details.

Please send us all feedback and issues you might have via the mailing list, or in case of a bug, via GitHub.

The tarball (signature) is available from our download server and packages for several distributions are available from our repository.

With this 4.5.1 release, the 4.2.x releases will be EOL and the 4.3.x and 4.4.x releases will go into critical fixes only mode. Consult the EOL policy for more details.

We would also like to announce that with this release we will stop supporting systems using 32-bit time. This includes 32-bit Linux platforms like arm6, arm7, and i386.

We are grateful to the PowerDNS community for the reporting of bugs, issues, feature requests, and especially to the submitters of fixes and implementations of features.