gnupg: key spoofing [LWN.net]

Package(s):

gnupg, gnupg2

CVE #(s):

Created:

September 17, 2012

Updated:

September 21, 2012

Description:

From the Ubuntu advisory:

It was discovered that GnuPG used a short ID when downloading keys from a keyserver, even if a long ID was requested. An attacker could possibly use this to return a different key with a duplicate short key id.

Alerts:

Ubuntu

USN-1570-1

2012-09-17

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gnupg: key spoofing

Posted Sep 21, 2012 7:31 UTC (Fri) by dd9jn (subscriber, #4459) [Link]

I have to chime in on this. First, older keyservers don't work with long keyids. Thus GnuPG could thus not use them. Meanwhile almost all keyserver upgraded to SKS which supports requests with long keyids. Thus we recently dropped support for old keyservers.

Second,the idea that a MITM on the keyserver is a problem is totally bogus. There is no security at all in the keyservers; they are only a convenient resources to store and retrieve keys. OpenPGP keys are self-contained and provide their own security: self-, key-, and key-binding-signatures. Any attack must be on the keys or the validation system in use (e.g. the web of trust).