Debian: New pdns-recursor packages fix predictable randomness
Posted by Benjamin D. Thomas   
Debian Thomas Biege discovered that the upstream fix for the weak random number generator released in DSA-1544-1 was incomplete: Source port randomization did still not use difficult-to-predict random numbers. This is corrected in this security update.
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Debian Security Advisory DSA-1544-2                  security@debian.org
http://www.debian.org/security/                           Florian Weimer
July 16, 2008                         http://www.debian.org/security/faq
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Package        : pdns-recursor
Vulnerability  : insufficient randomness
Problem type   : remote
Debian-specific: no
CVE Id(s)      : CVE-2008-1637
Debian Bug     : 490069

Thomas Biege discovered that the upstream fix for the weak random number
generator released in DSA-1544-1 was incomplete:  Source port
randomization did still not use difficult-to-predict random numbers.
This is corrected in this security update.

Here is the text of the original advisory:

  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)

In the light of recent DNS-related developments (documented in DSAs
1603, 1604, 1605), we recommend that this update is installed as an
additional safety measure.  (The lack of source port randomization was
addressed in the 3.1.6 upstream version.)

In addition, this update incorporates the changed IP address of
L.ROOT-SERVERS.NET.

For the stable distribution (etch), this problem has been fixed in
version 3.1.4-1+etch2.

For the unstable distribution (sid), this problem has been fixed in
version 3.1.7-1.

We recommend that you upgrade your pdns-recursor package.

Upgrade instructions
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wget url
        will fetch the file for you
dpkg -i file.deb
        will install the referenced file.

If you are using the apt-get package manager, use the line for
sources.list as given below:

apt-get update
        will update the internal database
apt-get upgrade
        will install corrected packages

You may use an automated update by adding the resources from the
footer to the proper configuration.


Debian GNU/Linux 4.0 alias etch
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Source archives:

  http://security.debian.org/pool/updates/main/p/pdns-recursor/pdns-recursor_3.1.4-1+etch2.diff.gz
    Size/MD5 checksum:    34915 0d67af6859a24778f87137fb159b19d6
  http://security.debian.org/pool/updates/main/p/pdns-recursor/pdns-recursor_3.1.4.orig.tar.gz
    Size/MD5 checksum:   171270 e35d774e3282285a59a7f8038a036b61
  http://security.debian.org/pool/updates/main/p/pdns-recursor/pdns-recursor_3.1.4-1+etch2.dsc
    Size/MD5 checksum:     1198 264388cc310a18ffcede810e510d26dc

alpha architecture (DEC Alpha)

  http://security.debian.org/pool/updates/main/p/pdns-recursor/pdns-recursor_3.1.4-1+etch2_alpha.deb
    Size/MD5 checksum:   499184 d975957b892261bef540029738fbc816

amd64 architecture (AMD x86_64 (AMD64))

  http://security.debian.org/pool/updates/main/p/pdns-recursor/pdns-recursor_3.1.4-1+etch2_amd64.deb
    Size/MD5 checksum:   418498 f5c48c3dfa05a888c38416b7c3b1e9ee

i386 architecture (Intel ia32)

  http://security.debian.org/pool/updates/main/p/pdns-recursor/pdns-recursor_3.1.4-1+etch2_i386.deb
    Size/MD5 checksum:   433786 33e5e4d147b1f7408dee93f014845e4b

ia64 architecture (Intel ia64)

  http://security.debian.org/pool/updates/main/p/pdns-recursor/pdns-recursor_3.1.4-1+etch2_ia64.deb
    Size/MD5 checksum:   598166 f1b98150ec6cb205eb10d5dcc69f1684

powerpc architecture (PowerPC)

  http://security.debian.org/pool/updates/main/p/pdns-recursor/pdns-recursor_3.1.4-1+etch2_powerpc.deb
    Size/MD5 checksum:   434308 4d9376157024a98cb3217f884c74f42f

s390 architecture (IBM S/390)

  http://security.debian.org/pool/updates/main/p/pdns-recursor/pdns-recursor_3.1.4-1+etch2_s390.deb
    Size/MD5 checksum:   408966 87930fd404bbab5c43332711511fedc7


  These files will probably be moved into the stable distribution on
  its next update.

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For apt-get: deb http://security.debian.org/ stable/updates main
For dpkg-ftp: ftp://security.debian.org/debian-security dists/stable/updates/main
Mailing list: debian-security-announce@lists.debian.org