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Fencer Vulns
medium 6.5

CVE-2020-13645 json

In GNOME glib-networking through 2.64.2, the implementation of GTlsClientConnection skips hostname verification of the server's TLS certifi…

published 2020-05-28 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-5887

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.0%
EPSS 2.0% chance of exploitation in 30 days, percentile 81%
public exploits
0
none known

Summary

In GNOME glib-networking through 2.64.2, the implementation of GTlsClientConnection skips hostname verification of the server's TLS certificate if the application fails to specify the expected server identity. This is in contrast to its intended documented behavior, to fail the certificate verification. Applications that fail to provide the server identity, including Balsa before 2.5.11 and 2.6.x before 2.6.1, accept a TLS certificate if the certificate is valid for any host.

Patch / fix

  • gnome balsa 2.5.11
  • gnome glib-networking 2.62.4, 2.64.3
  • glib-networking Debian 14, Debian 13, Debian 12 2.64.3-2

debian advisories DEBIAN-CVE-2020-13645

  • balsa Ubuntu 20.04 LTS 2.6.0-2ubuntu0.1
  • glib-networking Ubuntu 16.04 LTS 2.48.2-1~ubuntu16.04.2
  • glib-networking Ubuntu 18.04 LTS 2.56.0-1ubuntu0.1
  • glib-networking Ubuntu 20.04 LTS 2.64.2-1ubuntu0.1

ubuntu advisories UBUNTU-CVE-2020-13645

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • glib-networking SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +10 more 2.48.2-6.3.1
  • glib-networking SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +7 more 2.54.1-3.6.1
  • glib-networking SLE Module for Basesystem 15 SP3, SLE Module for Basesystem 15 SP2, SLE Micro 5.1 +1 more 2.62.4-3.3.1

suse advisories SUSE-SU-2021:4004-1SUSE-SU-2021:3997-1SUSE-SU-2021:3944-1

  • glib-networking openSUSE Tumbleweed 2.68.1-1.3
  • glib-networking openSUSE Leap 15.2 2.62.4-lp152.2.3.1
  • glib-networking openSUSE Leap 15.3 2.62.4-3.3.1
  • balsa Package Hub 15 SP3, Package Hub 15 SP2, openSUSE Leap 15.3 +1 more 2.6.1-bp153.2.3.1

opensuse advisories openSUSE-SU-2024:10790-1openSUSE-SU-2021:1554-1openSUSE-SU-2021:3944-1openSUSE-SU-2021:1094-1

  • glib-networking Alpine 3.24, Alpine 3.23, Alpine 3.22 +10 more 2.64.3-r0

alpine advisories ALPINE-CVE-2020-13645

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • glib-networking CBL-Mariner 2.0 2.59.1-8

azure linux advisories AZL-6440

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-13645 updated cvss 6.5

glib-networking: GTlsClientConnection silently ignores unset server identity

  • Red Hat Enterprise Linux 6 glib-networking
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 glib-networking, glib-networking-tests Red Hat Enterprise Linux 8 glib-networking
    affected: no fix planned “Will not fix”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.02% chance of exploitation in the next 30 days, higher than 81% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • gitlab.gnome.org https://gitlab.gnome.org/GNOME/glib-networking/-/issues/135 referenced PoC, tagged "exploit" by a source, unverified
  • gitlab.gnome.org https://gitlab.gnome.org/GNOME/balsa/-/issues/34 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD 2.0 6.4 AV:N/AC:L/Au:N/C:P/I:P/A:N

Classification

Weakness
  • CWE-295 Improper Certificate Validation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.