[Security] Bump urllib3 from 1.26.15 to 1.26.18

Bumps urllib3 from 1.26.15 to 1.26.18. This update includes security fixes.

Vulnerabilities fixed

Cookie HTTP header isn't stripped on cross-origin redirects urllib3 doesn't treat the Cookie HTTP header special or provide any helpers for managing cookies over HTTP, that is the responsibility of the user. However, it is possible for a user to specify a Cookie header and unknowingly leak information via HTTP redirects to a different origin if that user doesn't disable redirects explicitly.

Users must handle redirects themselves instead of relying on urllib3's automatic redirects to achieve safe processing of the Cookie header, thus we decided to strip the header by default in order to further protect users who aren't using the correct approach.

Affected usages

We believe the number of usages affected by this advisory is low. It requires all of the following to be true to be exploited:

• Using an affected version of urllib3 (patched in v1.26.17 and v2.0.6)
• Using the Cookie header on requests, which is mostly typical for impersonating a browser.
• Not disabling HTTP redirects
• Either not using HTTPS or for the origin server to redirect to a malicious origin.

Remediation

• Upgrading to at least urllib3 v1.26.17 or v2.0.6
• Disabling HTTP redirects using redirects=False when sending requests.
• Not using the Cookie header.

Patched versions: 1.26.17 Affected versions: < 1.26.17

urllib3's request body not stripped after redirect from 303 status changes request method to GET urllib3 previously wouldn't remove the HTTP request body when an HTTP redirect response using status 303 "See Other" after the request had its method changed from one that could accept a request body (like POST) to GET as is required by HTTP RFCs. Although the behavior of removing the request body is not specified in the section for redirects, it can be inferred by piecing together information from different sections and we have observed the behavior in other major HTTP client implementations like curl and web browsers.

From RFC 9110 Section 9.3.1:

A client SHOULD NOT generate content in a GET request unless it is made directly to an origin server that has previously indicated, in or out of band, that such a request has a purpose and will be adequately supported.

Affected usages

Because the vulnerability requires a previously trusted service to become compromised in order to have an impact on confidentiality we believe the exploitability of this vulnerability is low. Additionally, many users aren't putting sensitive data in HTTP request bodies, if this is the case then this vulnerability isn't exploitable.

Both of the following conditions must be true to be affected by this vulnerability:

• If you're using urllib3 and submitting sensitive information in the HTTP request body (such as form data or JSON)
• The origin service is compromised and starts redirecting using 303 to a malicious peer or the redirected-to service becomes compromised.

Remediation

You can remediate this vulnerability with any of the following steps:

• Upgrade to a patched version of urllib3 (v1.26.18 or v2.0.7)

... (truncated)

Patched versions: 1.26.18 Affected versions: <= 1.26.17

Release notes

Sourced from urllib3's releases.

1.26.18

• Made body stripped from HTTP requests changing the request method to GET after HTTP 303 "See Other" redirect responses. (GHSA-g4mx-q9vg-27p4)

1.26.17

• Added the Cookie header to the list of headers to strip from requests when redirecting to a different host. As before, different headers can be set via Retry.remove_headers_on_redirect. (GHSA-v845-jxx5-vc9f)

1.26.16

• Fixed thread-safety issue where accessing a PoolManager with many distinct origins would cause connection pools to be closed while requests are in progress (#2954)

Changelog

Sourced from urllib3's changelog.

1.26.18 (2023-10-17)

• Made body stripped from HTTP requests changing the request method to GET after HTTP 303 "See Other" redirect responses.

1.26.17 (2023-10-02)

• Added the Cookie header to the list of headers to strip from requests when redirecting to a different host. As before, different headers can be set via Retry.remove_headers_on_redirect. ([#3139](https://github.com/urllib3/urllib3/issues/3139) <https://github.com/urllib3/urllib3/pull/3139>_)

1.26.16 (2023-05-23)

• Fixed thread-safety issue where accessing a PoolManager with many distinct origins would cause connection pools to be closed while requests are in progress ([#2954](https://github.com/urllib3/urllib3/issues/2954) <https://github.com/urllib3/urllib3/pull/2954>_)

Commits

• 9c2c230 Release 1.26.18 (#3159)
• b594c5c Merge pull request from GHSA-g4mx-q9vg-27p4
• 944f0eb [1.26] Use vendored six in urllib3.contrib.securetransport
• c9016bf Release 1.26.17
• 0122035 Backport GHSA-v845-jxx5-vc9f (#3139)
• e63989f Fix installing brotli extra on Python 2.7
• 2e7a24d [1.26] Configure OS for RTD to fix building docs
• 57181d6 [1.26] Improve error message when calling urllib3.request() (#3058)
• 3c01480 [1.26] Run coverage even with failed jobs
• d94029b Release 1.26.16
• Additional commits viewable in compare view