CVE-2019-13050

Publication date 29 June 2019

Last updated 24 July 2024

Ubuntu priority

Low

Why this priority?

Cvss 3 Severity Score

7.5 · High

Score breakdown

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
gnupg 24.10 oracular Not in release
24.04 LTS noble Not in release
23.10 mantic Not in release
23.04 lunar Not in release
22.10 kinetic Not in release
22.04 LTS jammy Not in release
21.10 impish Not in release
21.04 hirsute Not in release
20.10 groovy Not in release
20.04 LTS focal Not in release
19.10 eoan Not in release
19.04 disco Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial
Vulnerable, fix deferred
14.04 LTS trusty Ignored end of ESM support, was deferred [2022-03-22]
gnupg2 24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
21.10 impish
Not affected
21.04 hirsute
Not affected
20.10 groovy
Not affected
20.04 LTS focal
Not affected
19.10 eoan Ignored end of life
19.04 disco Ignored end of life
18.04 LTS bionic
Fixed 2.2.4-1ubuntu1.5
16.04 LTS xenial Ignored change too intrusive
14.04 LTS trusty Not in release
sks 24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
21.10 impish
Not affected
21.04 hirsute
Not affected
20.10 groovy Not in release
20.04 LTS focal
Vulnerable, fix deferred
19.10 eoan Ignored end of life
19.04 disco Ignored end of life
18.10 cosmic Ignored end of life
18.04 LTS bionic
Vulnerable, fix deferred
16.04 LTS xenial
Vulnerable, fix deferred
14.04 LTS trusty Not in release

Notes

mdeslaur

this is a weakness in the PGP keyserver design.

alexmurray

gnupg upstream has 2 mitigations for this - firstly, don't import key signatures by default anymore, and to fallback to only import self-signatures on very large keyblocks

mdeslaur

as of 2020-01-06, there is no ideal fix for this issue marking this CVE as deferred until a complete fix is available

sbeattie

gnupg mitigations landed in upstream in 2.2.17 with important fixes in 2.2.18 2.2.19-3ubuntu1 introduced a debian/ubuntu specific change to use keys.openpgp.org as the default keyserver any backports to address this issue will be complex and introduce changes in behavior sks in debian introduced very basic filtering in 1.1.6+git20210302.c3ba6d5a-1

rodrigo-zaiden

as of 2022-03-22, there is no upstream backport for gnupg 1.4 series. Backporting from 2.2 is too risky.

Severity score breakdown

Parameter Value
Base score 7.5 · High
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact None
Availability impact High
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H