- ------------------------------------------------------------------------ Debian Security Advisory DSA-010-1 security@debian.org Debian -- Security Information Wichert Akkerman December 25, 2000 - ------------------------------------------------------------------------ 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 - ----------------------------------------------------- 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 - ------------------------------------ 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 - --------------------------------- Potato was released for alpha, arm, i386, m68k, powerpc and sparc. Source archives: MD5 checksum: 3e6a792f3bbb566650ea37a286feedf4 MD5 checksum: 866059ad036f47c59bad9e5c3a0f0749 MD5 checksum: bef2267bfe9b74a00906a78db34437f9 Alpha architecture: MD5 checksum: 616e391a4eb5561bf32714e40bed38c5 ARM architecture: MD5 checksum: e496f7aed98098feef2869be81b774b7 Intel ia32 architecture: MD5 checksum: a6c0494c737250b0ccc7dc33056d8e7c Motorola 680x0 architecture: MD5 checksum: a07cbf5bce2890fe85cfae4d796c5b0d PowerPC architecture: MD5 checksum: e251364c24066cc88a3de11b4ba23275 Sun Sparc architecture: MD5 checksum: b15f4ad07949fb0fa24a221b656691ae These files will be moved into soon. For not yet released architectures please refer to the appropriate directory . - -- - ---------------------------------------------------------------------------- apt-get: deb Debian -- Security Information stable/updates main dpkg-ftp: dists/stable/updates/main Mailing list: debian-security-announce@lists.debian.org