CVE-2018-20060

Severity: critical (CVSS 9.8 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 4.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-12-11 · updated 2026-06-17

Description

urllib3 before version 1.23 does not remove the Authorization HTTP header when following a cross-origin redirect (i.e., a redirect that differs in host, port, or scheme). This can allow for credentials in the Authorization header to be exposed to unintended hosts or transmitted in cleartext.

Affected products

Fedoraproject Fedora: 28, 29, 30
urllib3: before 1.23 — fixed in 1.23

How to fix

Upgrade to a fixed version: urllib3 1.23. Check the vendor advisory for mitigations.

References

http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00039.html
https://access.redhat.com/errata/RHSA-2019:2272
https://bugzilla.redhat.com/show_bug.cgi?id=1649153
https://github.com/urllib3/urllib3/blob/master/CHANGES.rst
https://github.com/urllib3/urllib3/issues/1316
https://github.com/urllib3/urllib3/pull/1346
https://lists.debian.org/debian-lts-announce/2021/06/msg00015.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5SJERZEJDSUYQP7BNBXMBHRHGY26HRZD/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BXLAXHM3Z6DUCXZ7ZXZ2EAYJXWDCZFCT/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XWP36YW3KSVLXDBY3QJKDYEPCIMN3VQZ/
https://usn.ubuntu.com/3990-1/
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00039.html

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