Red Hat: GnuPG Signing key vulnerability
Summary
Summary
GnuPG is a utility for encrypting data and creating digital signatures.Phong Nguyen identified a severe bug in the way GnuPG creates and usesElGamal keys, when those keys are used both to sign and encrypt data. Thisvulnerability can be used to trivially recover the private key. While thedefault behavior of GnuPG when generating keys does not lead to thecreation of unsafe keys, by overriding the default settings an unsafe keycould have been created.If you are using ElGamal keys, you should revoke those keys immediately.The packages included in this update do not make ElGamal keys safe to use;they merely include a patch by David Shaw that disables functions thatwould generate or use ElGamal keys.To determine if your key is affected, run the following command to obtain alist of secret keys that you have on your secret keyring:gpg --list-secret-keysThe output of this command includes both the size and type of the keysfound, and will look similar to this example:/home/example/.gnupg/secring.gpg- ----------------------------------------------------sec 1024D/01234567 2000-10-17 Example User <example@>uid Example User <example@>The key length, type, and ID are listed together, separated by a forwardslash. In the example output above, the key's type is "D" (DSA, signand encrypt). Your key is unsafe if and only if the key type is "G"(ElGamal, sign and encrypt). In the above example, the secret key is safeto use, while the secret key in the following example is not:/home/example/.gnupg/secring.gpg- ----------------------------------------------------sec 1024G/01234567 2000-10-17 Example User <example@>uid Example User <example@>For more details regarding this issue, as well as instructions on how torevoke any keys that are unsafe, refer to the advisory available from theGnuPG web site: The GNU Privacy Guard
Solution
Before applying this update, make sure all previously released errata
relevant to your system have been applied.
To update all RPMs for your particular architecture, run:
rpm -Fvh [filenames]
where [filenames] is a list of the RPMs you wish to upgrade. Only those
RPMs which are currently installed will be updated. Those RPMs which are
not installed but included in the list will not be updated. Note that you
can also use wildcards (*.rpm) if your current directory *only* contains
the desired RPMs.
Please note that this update is also available via Red Hat Network. Many
people find this an easier way to apply updates. To use Red Hat Network,
launch the Red Hat Update Agent with the following command:
up2date
This will start an interactive process that will result in the appropriate
RPMs being upgraded on your system.
If up2date fails to connect to Red Hat Network due to SSL Certificate
Errors, you need to install a version of the up2date client with an updated
certificate. The latest version of up2date is available from the Red Hat
FTP site and may also be downloaded directly from the RHN website:
5. RPMs required:
Red Hat Linux 7.1:
SRPMS:
i386:
Red Hat Linux 7.2:
SRPMS:
i386:
ia64:
Red Hat Linux 7.3:
SRPMS:
i386:
Red Hat Linux 8.0:
SRPMS:
i386:
Red Hat Linux 9:
SRPMS:
i386:
6. Verification:
MD5 sum Package Name
4d62554490e85b7cc1f0cfef6518a979 7.1/en/os/SRPMS/gnupg-1.0.7-12.src.rpm
0591a2079aff5e7979b0225b568bceaa 7.1/en/os/i386/gnupg-1.0.7-12.i386.rpm
b619c30c293094d7dcd18487d8e62a43 7.2/en/os/SRPMS/gnupg-1.0.7-13.src.rpm
e7e3e75afd1ccd2267ccc7847c76ebb4 7.2/en/os/i386/gnupg-1.0.7-13.i386.rpm
6fb21011ca42ff395b8cfc7dce4c2936 7.2/en/os/ia64/gnupg-1.0.7-13.ia64.rpm
b619c30c293094d7dcd18487d8e62a43 7.3/en/os/SRPMS/gnupg-1.0.7-13.src.rpm
e7e3e75afd1ccd2267ccc7847c76ebb4 7.3/en/os/i386/gnupg-1.0.7-13.i386.rpm
bc375882f13e5c10eb29eb3615de911d 8.0/en/os/SRPMS/gnupg-1.0.7-14.src.rpm
a3de0844778cd994258f121330ff6d62 8.0/en/os/i386/gnupg-1.0.7-14.i386.rpm
e1f31f4a07ebb5b4040f8f6ca3816cc4 9/en/os/SRPMS/gnupg-1.2.1-9.src.rpm
604a2fb5b809ec99280871f46507f4a1 9/en/os/i386/gnupg-1.2.1-9.i386.rpm
These packages are GPG signed by Red Hat for security. Our key is
available from https://access.redhat.com/security/team/key
You can verify each package with the following command:
rpm --checksig -v
If you only wish to verify that each package has not been corrupted or
tampered with, examine only the md5sum with the following command:
md5sum
References
http://lists.gnupg.org/pipermail/gnupg-announce/2003q4/000276.html How can one tell what kind of a key one has set up? http://lists.gnupg.org/pipermail/gnupg-announce/2003q4/000277.html CVE -CVE-2003-0971
Package List
Topic
Topic
Updated gnupg packages are now available for Red Hat Linux. These updates
disable the ability to generate ElGamal keys (used for both signing and
encrypting) and disable the ability to use ElGamal public keys for
encrypting data.
Relevant Releases Architectures
Red Hat Linux 7.1 - i386
Red Hat Linux 7.2 - i386, ia64
Red Hat Linux 7.3 - i386
Red Hat Linux 8.0 - i386
Red Hat Linux 9 - i386
Bugs Fixed
