What’s Vulnerable › Vulnerabilities

CVE-2020-13645

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.0% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2020-05-28 · updated 2026-06-17
• Weakness: CWE-295

Description

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.

Affected products

• Brocade Fabric OS: all versions
• Canonical Ubuntu Linux: 16.04, 18.04, 19.10, 20.04
• Fedoraproject Fedora: 31, 32
• GNOME Balsa: before 2.5.11; 2.6.0 — fixed in 2.5.11
• GNOME Glib-Networking: before 2.62.4; from 2.64.0 before 2.64.3 — fixed in 2.62.4, 2.64.3
• NetApp Cloud Backup: all versions

How to fix

Upgrade to a fixed version: GNOME Balsa 2.5.11; GNOME Glib-Networking 2.62.4, 2.64.3. Check the vendor advisory for mitigations.

References

• https://gitlab.gnome.org/GNOME/balsa/-/issues/34
• https://gitlab.gnome.org/GNOME/glib-networking/-/issues/135
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HLEX2IP62SU6WJ4SK3U766XGLQK3J62O/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LRCUM22YEWWKNMN2BP5LTVDM5P4VWIXS/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TQEQJQ4XFMFCFJTEXKL2ZO3UELBPCKSK/
• https://security.gentoo.org/glsa/202007-50
• https://security.netapp.com/advisory/ntap-20200608-0004/
• https://usn.ubuntu.com/4405-1/
• https://gitlab.gnome.org/GNOME/balsa/-/issues/34
• https://gitlab.gnome.org/GNOME/glib-networking/-/issues/135
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HLEX2IP62SU6WJ4SK3U766XGLQK3J62O/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LRCUM22YEWWKNMN2BP5LTVDM5P4VWIXS/

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