Bug 1213377 (CVE-2015-1868)

Summary:	CVE-2015-1868 pdns: Label decompression bug in PowerDNS can cause crashes on specific platforms
Product:	[Other] Security Response	Reporter:	Vasyl Kaigorodov <vkaigoro>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	carnil, mstevens, peter.van.dijk, ruben, security-response-team
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	PowerDNS Recursor 3.6.3, PowerDNS Recursor 3.7.2, PowerDNS Authoritative Server 3.4.4	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-06-10 20:34:36 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:	1213832, 1214703
Bug Blocks:

Description Vasyl Kaigorodov 2015-04-20 12:28:23 UTC

PowerDNS project has reported the following issue in PowerDNS:
"""
A bug was discovered in our label decompression code, making it possible for
names to refer to themselves, thus causing a loop during decompression. This
loop is capped at a 1000 iterations by a failsafe, making the issue harmless
on most platforms.

However, on specific platforms , the recursion involved in these 1000 steps causes memory
corruption leading to a quick crash, presumably because the default stack is
too small.

We recommend that all users upgrade to a corrected version if at all possible.
Alternatively, if you want to apply a minimal fix to your own tree, it can be
found in two parts:
https://github.com/PowerDNS/pdns/commit/adb10be102ddd4d2baf7a8adbb5673946fe5e555
https://github.com/PowerDNS/pdns/commit/3ec3e0fc71bc89ac41c7e6d8cd3f323f25233881
These should be trivial to backport to older versions by hand.

As for workarounds, only clients in allow-from are able to trigger the
degraded service, so this should be limited to your userbase; further,  we
recommend running your critical services under supervision such as systemd,
supervisord, daemontools, etc.
"""

Acknowledements:

Red Hat would like to thank the PowerDNS upstream project for reporting this issue. Upstream acknowledges Aki Tuomi as the original reporter.

Comment 1 Martin Prpič 2015-04-23 12:19:11 UTC

Created pdns tracking bugs for this issue:

Affects: fedora-all [bug 1214703]
Affects: epel-5 [bug 1213832]

Comment 2 Martin Prpič 2015-04-23 12:23:15 UTC

External References:

https://doc.powerdns.com/md/security/powerdns-advisory-2015-01/

Comment 3 Fedora Update System 2015-04-29 19:17:17 UTC

pdns-recursor-3.7.2-1.el6 has been pushed to the Fedora EPEL 6 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 4 Fedora Update System 2015-04-29 19:17:25 UTC

pdns-recursor-3.7.2-1.el7 has been pushed to the Fedora EPEL 7 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 5 Fedora Update System 2015-04-29 19:17:39 UTC

pdns-3.3.1-2.el6 has been pushed to the Fedora EPEL 6 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 6 Fedora Update System 2015-04-29 19:20:36 UTC

pdns-recursor-3.6.3-1.el5 has been pushed to the Fedora EPEL 5 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 7 Fedora Update System 2015-04-29 19:20:43 UTC

pdns-3.4.4-1.el7 has been pushed to the Fedora EPEL 7 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 8 Fedora Update System 2015-04-30 11:39:20 UTC

pdns-recursor-3.7.2-1.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 9 Fedora Update System 2015-04-30 11:40:16 UTC

pdns-recursor-3.7.2-1.fc22 has been pushed to the Fedora 22 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 10 Fedora Update System 2015-04-30 11:41:41 UTC

pdns-3.3.1-3.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 11 Fedora Update System 2015-04-30 11:43:37 UTC

pdns-3.4.4-1.fc21 has been pushed to the Fedora 21 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 12 Fedora Update System 2015-04-30 11:46:07 UTC

pdns-recursor-3.7.2-1.fc21 has been pushed to the Fedora 21 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 13 Fedora Update System 2015-04-30 11:48:18 UTC

pdns-3.4.4-1.fc22 has been pushed to the Fedora 22 stable repository.  If problems still persist, please make note of it in this bug report.