The PowerDNS Recursor is an advanced recursing nameserver.
Amit Klein of Trusteer reported that insufficient randomness is used to calculate the TRXID values and the UDP source port numbers (CVE-2008-1637). Thomas Biege of SUSE pointed out that a prior fix to resolve this issue was incomplete, as it did not always enable the stronger random number generator for source port selection (CVE-2008-3217).
A remote attacker could send malicious answers to insert arbitrary DNS data into the cache. These attacks would in turn help an attacker to perform man-in-the-middle and site impersonation attacks.
There is no known workaround at this time.
All PowerDNS Recursor users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-dns/pdns-recursor-3.1.6"