full-disclosure-uk January 2009 archive
Main Archive Page > Month Archives  > full-disclosure-uk archives
full-disclosure-uk: [Full-disclosure] [ GLSA 200901-03 ] pdnsd:

[Full-disclosure] [ GLSA 200901-03 ] pdnsd: Denial of Service and cache poisoning

From: Robert Buchholz <rbu_at_nospam>
Date: Sun Jan 11 2009 - 00:41:31 GMT
To: gentoo-announce@gentoo.org

  • - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gentoo Linux Security Advisory GLSA 200901-03
  • - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - http://security.gentoo.org/
  • - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Severity: Normal Title: pdnsd: Denial of Service and cache poisoning Date: January 11, 2009 Bugs: #231285 ID: 200901-03
  • - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Synopsis


Two errors in pdnsd allow for Denial of Service and cache poisoning.

Background


pdnsd is a proxy DNS server with permanent caching that is designed to cope with unreachable DNS servers.

Affected packages



Package / Vulnerable / Unaffected ------------------------------------------------------------------- 1 net-dns/pdnsd < 1.2.7 >= 1.2.7

Description


Two issues have been reported in pdnsd:

  • The p_exec_query() function in src/dns_query.c does not properly handle many entries in the answer section of a DNS reply, related to a "dangling pointer bug" (CVE-2008-4194).
  • The default value for query_port_start was set to 0, disabling UDP source port randomization for outgoing queries (CVE-2008-1447).

Impact


An attacker could exploit the second weakness to poison the cache of pdnsd and thus spoof DNS traffic, which could e.g. lead to the redirection of web or mail traffic to malicious sites. The first issue can be exploited by enticing pdnsd to send a query to a malicious DNS server, or using the port randomization weakness, and might lead to a Denial of Service.

Workaround


Port randomization can be enabled by setting the "query_port_start" option to 1024 which would resolve the CVE-2008-1447 issue.

Resolution


All pdnsd users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=net-dns/pdnsd-1.2.7"

References


  [ 1 ] CVE-2008-1447
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-1447   [ 2 ] CVE-2008-4194
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-4194

Availability


This GLSA and any updates to it are available for viewing at the Gentoo Security Website:

  http://security.gentoo.org/glsa/glsa-200901-03.xml

Concerns?


Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at http://bugs.gentoo.org.

License


Copyright 2009 Gentoo Foundation, Inc; referenced text belongs to its owner(s).

The contents of this document are licensed under the Creative Commons - Attribution / Share Alike license.

http://creativecommons.org/licenses/by-sa/2.5



Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/