Debian: 'gnupg' vulnerabilities
Posted by LinuxSecurity.com Team   
Debian Two bugs in GnuPG have recently been found:

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Debian Security Advisory DSA-010-1                   security@debian.org 
http://www.debian.org/security/                         Wichert Akkerman
December 25, 2000
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Package        : gnupg
Problem type   : cheating with detached signatures,
                 circumvention of web of trust
Debian-specific: no

Two bugs in GnuPG have recently been found:

1. false positives when verifying detached signatures
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There is a problem in the way gpg checks detached signatures which
can lead to false positives. Detached signature can be verified
with a command like this:

     gpg --verify detached.sig < mydata

If someone replaced detached.sig with a signed text (ie not a
detached signature) and then modified mydata gpg would still
report a successfully verified signature.

To fix the way the --verify option works has been changes: it now
needs two options when verifying detached signatures: both the file
with the detached signature, and the file with the data to be
verified. Please note that this makes it incompatible with older
versions! 

2. secret keys are silently imported
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Florian Weimer discovered that gpg would import secret keys from
key-servers. Since gpg considers public keys corresponding to
known secret keys to be ultimately trusted an attacked can use this
circumvent the web of trust.

To fix this a new option was added to to tell gpg it is allowed
to import secret keys: --allow-key-import.


Both these fixes are in version 1.0.4-1.1 and we recommend that you
upgrade your gnupg package immediately.

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


Debian GNU/Linux 2.2 alias potato
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  Potato was released for alpha, arm, i386, m68k, powerpc and sparc.

  Source archives:
     http://security.debian.org/dists/stable/updates/main/source/gnupg_1.0.4-1.1.diff.gz
      MD5 checksum: 3e6a792f3bbb566650ea37a286feedf4
     http://security.debian.org/dists/stable/updates/main/source/gnupg_1.0.4-1.1.dsc
      MD5 checksum: 866059ad036f47c59bad9e5c3a0f0749
     http://security.debian.org/dists/stable/updates/main/source/gnupg_1.0.4.orig.tar.gz
      MD5 checksum: bef2267bfe9b74a00906a78db34437f9

  Alpha architecture:
     http://security.debian.org/dists/stable/updates/main/binary-alpha/gnupg_1.0.4-1.1_alpha.deb
      MD5 checksum: 616e391a4eb5561bf32714e40bed38c5

  ARM architecture:
     http://security.debian.org/dists/stable/updates/main/binary-arm/gnupg_1.0.4-1.1_arm.deb
      MD5 checksum: e496f7aed98098feef2869be81b774b7

  Intel ia32 architecture:
     http://security.debian.org/dists/stable/updates/main/binary-i386/gnupg_1.0.4-1.1_i386.deb
      MD5 checksum: a6c0494c737250b0ccc7dc33056d8e7c

  Motorola 680x0 architecture:
     http://security.debian.org/dists/stable/updates/main/binary-m68k/gnupg_1.0.4-1.1_m68k.deb
      MD5 checksum: a07cbf5bce2890fe85cfae4d796c5b0d

  PowerPC architecture:
     http://security.debian.org/dists/stable/updates/main/binary-powerpc/gnupg_1.0.4-1.1_powerpc.deb
      MD5 checksum: e251364c24066cc88a3de11b4ba23275

  Sun Sparc architecture:
     http://security.debian.org/dists/stable/updates/main/binary-sparc/gnupg_1.0.4-1.1_sparc.deb
      MD5 checksum: b15f4ad07949fb0fa24a221b656691ae

  These files will be moved into
   ftp://ftp.debian.org/debian/dists/stable/*/binary-$arch/ soon.

For not yet released architectures please refer to the appropriate
directory  ftp://ftp.debian.org/debian/dists/sid/binary-$arch/ .

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