Stay Secure with the Latest Linux Advisories

security advisorydenial of servicegentoo

Gentoo: 200901-03 Critical: pdnsd Cache Poisoning And DoS Exploit

Two errors in pdnsd allow for Denial of Service and cache poisoning.. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gentoo Linux Security Advisory GLSA 200901-03 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - https://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" optionto 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 https://www.cve.org/CVERecord?id=CVE-2008-1447 [ 2 ] CVE-2008-4194 https://www.cve.org/CVERecord?id=CVE-2008-4194 Availability =========== This GLSA and any updates to it are available for viewing at the Gentoo Security Website: https://security.gentoo.org/glsa/200901-03 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 This email address is being protected from spambots. You need JavaScript enabled to view it. or alternatively, you may file a bug at https://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. https://creativecommons.org/licenses/by-sa/2.5/ . Gentoo alert regarding vulnerabilities in pdnsd leading to possible service disruption and cache exploitation. Immediate update advised for protection.. pdnsd Denial of Service, cache poisoning, Gentoo advisory. . LinuxSecurity.com Team

Jan 11, 2009 Gentoo