GLSA Advocate
Joined: 12 May 2004 Posts: 2663
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Posted: Sun Jan 11, 2009 3:26 am Post subject: [ GLSA 200901-03 ] pdnsd: Denial of Service and cache poison |
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Gentoo Linux Security Advisory
Title: pdnsd: Denial of Service and cache poisoning (GLSA 200901-03)
Severity: normal
Exploitable: remote
Date: January 11, 2009
Bug(s): #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: net-dns/pdnsd
Vulnerable: < 1.2.7
Unaffected: >= 1.2.7
Architectures: All supported architectures
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: Code: | # emerge --sync
# emerge --ask --oneshot --verbose ">=net-dns/pdnsd-1.2.7" |
References
CVE-2008-1447
CVE-2008-4194 |
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