[Announce] [security fix] GnuPG 2.2.23 released
wk at gnupg.org
Thu Sep 3 18:44:35 CEST 2020
We are pleased to announce the availability of a new GnuPG release:
version 2.2.23. This version fixes a *critical security bug* in
versions 2.2.21 and 2.2.22.
These versions are affected:
- GnuPG 2.2.21 (released 2020-07-09)
- GnuPG 2.2.22 (released 2020-08-27)
- Gpg4win 3.1.12 (released 2020-07-24)
All other versions are not affected.
Importing an OpenPGP key having a preference list for AEAD algorithms
will lead to an array overflow and thus often to a crash or other
Importing an arbitrary key can often easily be triggered by an attacker
and thus triggering this bug. Exploiting the bug aside from crashes is
not trivial but likely possible for a dedicated attacker. The major
hurdle for an attacker is that only every second byte is under their
control with every first byte having a fixed value of 0x04.
Software distribution verification should not be affected by this bug
because such a system uses a curated list of keys.
A CVE-id has not yet been assigned. We track this bug at
If GnuPG version 2.2.21 or 2.2.22 is in use please update ASAP to
If you are using an older version or a beta of version 2.3 no immediate
action is required.
If you are using Gpg4win 3.1.12 or GnuPG VS-Desktop 3.1.12 you may
either wait for a fixed release which we will provide very soon or
install GnuPG version 2.2.23 on top.
If installation of a new version is not possible, applying the patch
is also sufficient.
The GNU Privacy Guard (GnuPG, GPG) is a complete and free implementation
of the OpenPGP and S/MIME standards.
GnuPG allows to encrypt and sign data and communication, features a
versatile key management system as well as access modules for public key
directories. GnuPG itself is a command line tool with features for easy
integration with other applications. The separate library GPGME provides
a uniform API to use the GnuPG engine by software written in common
programming languages. A wealth of frontend applications and libraries
making use of GnuPG are available. As an universal crypto engine GnuPG
provides support for S/MIME and Secure Shell in addition to OpenPGP.
GnuPG is Free Software (meaning that it respects your freedom). It can
be freely used, modified and distributed under the terms of the GNU
General Public License.
Noteworthy changes in version 2.2.23
* gpg: Fix AEAD preference list overflow. [#5050]
* gpg: Fix a possible segv in the key cleaning code.
* gpgsm: Fix a minor RFC2253 parser bug. [#5037]
* scdaemon: Fix a PIN verify failure on certain OpenPGP card
implementations. Regression in 2.2.22. [#5039]
* po: Fix bug in the Hungarian translation. Updates for the Czech,
Polish, and Ukrainian translations.
Getting the Software
Please follow the instructions found at <https://gnupg.org/download/> or
GnuPG 2.2.23 may be downloaded from one of the GnuPG mirror sites or
direct from its primary FTP server. The list of mirrors can be found at
<https://gnupg.org/download/mirrors.html>. Note that GnuPG is not
available at ftp.gnu.org.
The GnuPG source code compressed using BZIP2 and its OpenPGP signature
are available here:
An installer for Windows without any graphical frontend except for a
very minimal Pinentry tool is available here:
The source used to build the Windows installer can be found in the same
directory with a ".tar.xz" suffix.
A new version of the GnuPG Desktop for Windows (aka Gpg4win) featuring
this version of GnuPG will be released shortly.
Checking the Integrity
In order to check that the version of GnuPG which you are going to
install is an original and unmodified one, you can do it in one of
the following ways:
* If you already have a version of GnuPG installed, you can simply
verify the supplied signature. For example to verify the signature
of the file gnupg-2.2.23.tar.bz2 you would use this command:
gpg --verify gnupg-2.2.23.tar.bz2.sig gnupg-2.2.23.tar.bz2
This checks whether the signature file matches the source file.
You should see a message indicating that the signature is good and
made by one or more of the release signing keys. Make sure that
this is a valid key, either by matching the shown fingerprint
against a trustworthy list of valid release signing keys or by
checking that the key has been signed by trustworthy other keys.
See the end of this mail for information on the signing keys.
* If you are not able to use an existing version of GnuPG, you have
to verify the SHA-1 checksum. On Unix systems the command to do
this is either "sha1sum" or "shasum". Assuming you downloaded the
file gnupg-2.2.23.tar.bz2, you run the command like this:
and check that the output matches the next line:
This version of GnuPG has support for 26 languages with Chinese
(traditional and simplified), Czech, French, German, Japanese,
Norwegian, Polish, Russian, and Ukrainian being almost completely
Documentation and Support
If you used GnuPG in the past you should read the description of
changes and new features at doc/whats-new-in-2.1.txt or online at
The file gnupg.info has the complete reference manual of the system.
Separate man pages are included as well but they miss some of the
details available only in thee manual. The manual is also available
or can be downloaded as PDF at
You may also want to search the GnuPG mailing list archives or ask on
the gnupg-users mailing list for advise on how to solve problems. Most
of the new features are around for several years and thus enough public
experience is available. https://wiki.gnupg.org has user contributed
information around GnuPG and relate software.
In case of build problems specific to this release please first check
https://dev.gnupg.org/T5045 for updated information.
Please consult the archive of the gnupg-users mailing list before
reporting a bug: <https://gnupg.org/documentation/mailing-lists.html>.
We suggest to send bug reports for a new release to this list in favor
of filing a bug at <https://bugs.gnupg.org>. If you need commercial
support go to <https://gnupg.com> or <https://gnupg.org/service.html>.
If you are a developer and you need a certain feature for your project,
please do not hesitate to bring it to the gnupg-devel mailing list for
Since 2001 maintenance and development of GnuPG is done by g10 Code GmbH
and currently mostly financed by donations. Two full-time employed
developers as well as two contractor exclusively work on GnuPG and
closely related software like Libgcrypt, GPGME and Gpg4win.
We like to thank all the nice people who are helping the GnuPG project,
be it testing, coding, translating, suggesting, auditing, administering
the servers, spreading the word, or answering questions on the mailing
Many thanks to our numerous financial supporters, both corporate and
individuals. Without you it would not be possible to keep GnuPG in a
good and secure shape and to address all the small and larger requests
made by our users. Thanks.
Special thanks to Andreas Stieger for reporting a bug and providing
detailed information for us to track this down.
Your GnuPG hackers
This is an announcement only mailing list. Please send replies only to
the gnupg-users'at'gnupg.org mailing list.
List of Release Signing Keys:
To guarantee that a downloaded GnuPG version has not been tampered by
malicious entities we provide signature files for all tarballs and
binary versions. The keys are also signed by the long term keys of
their respective owners. Current releases are signed by one or more
of these four keys:
rsa2048 2011-01-12 [expires: 2021-12-31]
Key fingerprint = D869 2123 C406 5DEA 5E0F 3AB5 249B 39D2 4F25 E3B6
Werner Koch (dist sig)
rsa2048 2014-10-29 [expires: 2020-10-30]
Key fingerprint = 031E C253 6E58 0D8E A286 A9F2 2071 B08A 33BD 3F06
NIIBE Yutaka (GnuPG Release Key) <gniibe 'at' fsij.org>
rsa3072 2017-03-17 [expires: 2027-03-15]
Key fingerprint = 5B80 C575 4298 F0CB 55D8 ED6A BCEF 7E29 4B09 2E28
Andre Heinecke (Release Signing Key)
ed25519 2020-08-24 [expires: 2030-06-30]
Key fingerprint = 6DAA 6E64 A76D 2840 571B 4902 5288 97B8 2640 3ADA
Werner Koch (dist signing 2020)
The keys are available at <https://gnupg.org/signature_key.html> and
in any recently released GnuPG tarball in the file g10/distsigkey.gpg .
Note that this mail has been signed by a different key.
# Please read: Daniel Ellsberg - The Doomsday Machine #
Die Gedanken sind frei. Ausnahmen regelt ein Bundesgesetz.
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