7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
0.01 Low
EPSS
Percentile
83.6%
Interaction between the sks-keyserver code through 1.2.0 of the SKS keyserver network, and GnuPG through 2.2.16, makes it risky to have a GnuPG keyserver configuration line referring to a host on the SKS keyserver network. Retrieving data from this network may cause a persistent denial of service, because of a Certificate Spamming Attack.
As per upstream: High-risk users should stop using the keyserver network immediately.
1. Open ~/.gnupg/gpg.conf in a text editor. Ensure there is no line starting with keyserver. If there is, remove it.
2. Open ~/.gnupg/dirmngr.conf in a text editor. Add the line "keyserver hkps://keys.openpgp.org" to the end of it.
keys.openpgp.org is a new experimental keyserver which is not part of the keyserver network and has some features which make it resistant to this attack. It is not a drop-in replacement: it has some limitations (for instance, its search functionality is sharply constrained). However, once you make this change you will be able to run gpg --refresh-keys with confidence.
For installations which are currently rendered unusable by this attack, the following repair method is advised:
1. If you know which certificate is likely poisoned, try deleting it. Once the installation becomes usable again, you can acquire a new unpoisoned copy of the certificate and re-import it.
2. If you do not know which certificate is poisoned, best option is to get a list of all your certificate IDs, delete your keyrings completely, and rebuild from scratch using known-good copies of the public certificates.
7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
0.01 Low
EPSS
Percentile
83.6%