Bug 1109231

Summary:	pdns: DoS due to maximum number of file descriptors exhausted
Product:	[Other] Security Response	Reporter:	Vasyl Kaigorodov <vkaigoro>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	jrusnack, ms, peter.van.dijk
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2014-06-13 16:57:48 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1109232, 1109233, 1109234, 1109235, 1109236, 1109237, 1109239
Bug Blocks:

Description Vasyl Kaigorodov 2014-06-13 13:13:34 UTC

It was found [1] that in default configuration PowerDNS is allowed to consume more file descriptors than is available for a default Linux installation.
This can potentially lead to the DoS attack.
Patch is available at [2]

External references:

  [1]: http://blog.powerdns.com/2014/02/06/related-to-recent-dos-attacks-recursor-configuration-file-guidance/
  [2]: https://github.com/Habbie/pdns/commit/e24b124a4c7b49f38ff8bcf6926cd69077d16ad8

Comment 1 Morten Stevens 2014-06-13 13:43:42 UTC

Hi,

1) It doesn't affect pdns. Only pdns-recursor is affected.

2) pdns-recursor for Fedora and Fedora-EPEL has already this patch.

Please check:
https://bugzilla.redhat.com/show_bug.cgi?id=1063304

http://pkgs.fedoraproject.org/cgit/pdns-recursor.git/commit/?id=28d9076a3f68177a3910dc9bdf27700e19dafc1e

https://admin.fedoraproject.org/updates/FEDORA-EPEL-2014-0524/pdns-recursor-3.5.3-2.el6
https://admin.fedoraproject.org/updates/FEDORA-EPEL-2014-0511/pdns-recursor-3.5.3-2.el5
https://admin.fedoraproject.org/updates/FEDORA-2014-2318/pdns-recursor-3.5.3-2.fc20
https://admin.fedoraproject.org/updates/FEDORA-2014-2246/pdns-recursor-3.5.3-2.fc19

Comment 2 Peter van Dijk (PowerDNS) 2014-06-13 14:03:52 UTC

As upstream developer, I confirm that this bug is only present in the Recursor ('pdns-recursor'), not in the Authoritative server ('pdns').

Comment 3 Vincent Danen 2014-06-13 16:57:48 UTC

Thanks for this, Peter, and the links to the fixed packages.