PowerDNS Recursor before 3.1.5 uses insufficient randomness to calculate (1) TRXID values and (2) UDP source port numbers, which makes it easier for remote attackers to poison a DNS cache, related to (a) algorithmic deficiencies in rand and random functions in external libraries, (b) use of a 32-bit seed value, and (c) choice of the time of day as the sole seeding information.

According to its self-reported version number, the version of PowerDNS Recursor listening on the remote host is version 3.x prior to 3.1.6.
It is, therefore, affected by a cache poisoning vulnerability due to insufficient randomness to calculate TRXID values and UDP source port numbers. A remote attacker can exploit this poison the DNS cache. This vulnerability was originally fixed in version 3.1.5, but a more secure method was implemented in version 3.1.6.

Note that Nessus has not attempted to exploit this issue but has instead relied only on the application's self-reported version number.
Also, Nessus has not checked for the presence of the patch or the workaround.

Pdns-recursor was prone to a spoofing vulnerability which could be abused to redirect clients or manipulate data. (CVE-2008-1637)

pdns used predictable random numbers for DNS responses. Therfore attackers could generate spoofed DNS responses (CVE-2008-1637).

The remote host is affected by the vulnerability described in GLSA-200804-22 (PowerDNS Recursor: DNS Cache Poisoning)

    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).
  Impact :

    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.
  Workaround :

    There is no known workaround at this time.

Amit Klein discovered that pdns-recursor, a caching DNS resolver, uses a weak random number generator to create DNS transaction IDs and UDP source port numbers. As a result, cache poisoning attacks were simplified. (CVE-2008-1637 and CVE-2008-3217 )

- Bug #440247 - CVE-2008-1637 pdns-recursor: perdictable     query ids

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

- Wed Apr 2 2008 Ruben Kerkhof <ruben at rubenkerkhof.com>     3.1.5-1

    - Upstream released new version

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
34044	PowerDNS Recursor 3.x < 3.1.6 DNS Predictable Transaction ID (TRXID) Cache Poisoning	Nessus	DNS	medium
33090	openSUSE 10 Security Update : pdns-recursor (pdns-recursor-5319)	Nessus	SuSE Local Security Checks	medium
33089	openSUSE 10 Security Update : pdns (pdns-5242)	Nessus	SuSE Local Security Checks	medium
32015	GLSA-200804-22 : PowerDNS Recursor: DNS Cache Poisoning	Nessus	Gentoo Local Security Checks	medium
31950	Debian DSA-1544-2 : pdns-recursor - design flaw	Nessus	Debian Local Security Checks	medium
31827	Fedora 8 : pdns-recursor-3.1.5-1.fc8 (2008-3036)	Nessus	Fedora Local Security Checks	medium
31824	Fedora 7 : pdns-recursor-3.1.5-1.fc7 (2008-3010)	Nessus	Fedora Local Security Checks	medium

Detections

Analytics

CVE-2008-1637

high

Tenable Plugins

medium

medium

medium

medium

medium

medium

medium