Bug 1821896 (CVE-2020-11501) - CVE-2020-11501 gnutls: DTLS client hello contains a random value of all zeroes
Summary: CVE-2020-11501 gnutls: DTLS client hello contains a random value of all zeroes
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2020-11501
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1821898 1821899 1822005 1826176
Blocks: 1821900
TreeView+ depends on / blocked
 
Reported: 2020-04-07 19:15 UTC by Guilherme de Almeida Suckevicz
Modified: 2021-02-16 20:18 UTC (History)
17 users (show)

Fixed In Version: gnutls 3.6.13
Clone Of:
Environment:
Last Closed: 2020-04-30 22:31:52 UTC
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2020:1998 0 None None None 2020-04-30 17:32:54 UTC

Description Guilherme de Almeida Suckevicz 2020-04-07 19:15:24 UTC
GnuTLS 3.6.x before 3.6.13 uses incorrect cryptography for DTLS. The earliest affected version is 3.6.3 (2018-07-16) because of an error in a 2017-10-06 commit. The DTLS client always uses 32 '\0' bytes instead of a random value, and thus contributes no randomness to a DTLS negotiation. This breaks the security guarantees of the DTLS protocol.

References:
https://gitlab.com/gnutls/gnutls/-/issues/960
https://www.gnutls.org/security-new.html#GNUTLS-SA-2020-03-31

Comment 1 Guilherme de Almeida Suckevicz 2020-04-07 19:17:09 UTC
Created gnutls tracking bugs for this issue:

Affects: fedora-all [bug 1821898]


Created mingw-gnutls tracking bugs for this issue:

Affects: fedora-all [bug 1821899]

Comment 2 Huzaifa S. Sidhpurwala 2020-04-08 03:47:53 UTC
Statement:

The earliest affected version is gnuTLS-3.6.3. Therefore versions of gnuTLS shipped with Red Hat Enterprise Linux 5, 6 and 7 are not affected by this flaw.

Comment 5 errata-xmlrpc 2020-04-30 17:32:52 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:1998 https://access.redhat.com/errata/RHSA-2020:1998

Comment 6 Product Security DevOps Team 2020-04-30 22:31:52 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2020-11501

Comment 7 Huzaifa S. Sidhpurwala 2020-05-16 03:34:14 UTC
External References:

https://www.redhat.com/en/blog/understanding-dtls-all-zero-clienthellorandom-vulnerability

Comment 8 Eddie Allen 2020-07-23 16:10:20 UTC
RHEL UBI8 images show the following:

$ docker pull registry.redhat.io/ubi8-minimal:latest && docker run -ti registry.redhat.io/ubi8-minimal:latest bash -c "rpm -aq | grep tls"
latest: Pulling from ubi8-minimal
Digest: sha256:5a857c1d77b1dbb72f11e6d95ca01c3dab947f0c95ca53a6a28eabf4f3f9463a
Status: Image is up to date for registry.redhat.io/ubi8-minimal:latest
registry.redhat.io/ubi8-minimal:latest
gnutls-3.6.8-11.el8_2.x86_64

Has this fix been ported to the gnutls-3.6.8-11.el8_2.x86_64 package that is shipped with UBI8?


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