[Security] Bump urllib3 from 1.25.6 to 1.25.9

[dependabot-preview]

Bumps urllib3 from 1.25.6 to 1.25.9.

Release notes

Sourced from urllib3's releases.

1.25.8

Release: 1.25.8

1.25.7

No release notes provided.

Changelog

Sourced from urllib3's changelog.

1.25.9 (2020-04-16)

• Added InvalidProxyConfigurationWarning which is raised when erroneously specifying an HTTPS proxy URL. urllib3 doesn't currently support connecting to HTTPS proxies but will soon be able to and we would like users to migrate properly without much breakage.

  See this GitHub issue for more information on how to fix your proxy config. (Pull #1851)

• Drain connection after PoolManager redirect (Pull #1817)

• Ensure load_verify_locations raises SSLError for all backends (Pull #1812)

• Rename VerifiedHTTPSConnection to HTTPSConnection (Pull #1805)

• Allow the CA certificate data to be passed as a string (Pull #1804)

• Raise ValueError if method contains control characters (Pull #1800)

• Add __repr__ to Timeout (Pull #1795)

1.25.8 (2020-01-20)

• Drop support for EOL Python 3.4 (Pull #1774)
• Optimize _encode_invalid_chars (Pull #1787)

1.25.7 (2019-11-11)

• Preserve chunked parameter on retries (Pull #1715, Pull #1734)
• Allow unset SERVER_SOFTWARE in App Engine (Pull #1704, Issue #1470)
• Fix issue where URL fragment was sent within the request target. (Pull #1732)
• Fix issue where an empty query section in a URL would fail to parse. (Pull #1732)
• Remove TLS 1.3 support in SecureTransport due to Apple removing support (Pull #1703)

Commits

• 21758b0 Release v1.25.9
• c930dc0 Add InvalidProxyConfigurationWarning for HTTPS proxies
• 2ec3438 Fix flaky test by setting longer connect timeout
• 262ac6b Backslash terminates authority URL section
• c392b6c Fix documentation build by skipping Sphinx 3.0.0 (#1844)
• 6580893 Revert "Add context to find_unused_port"
• 308a08f Unwrap ProxyError when evaluating retries (#1830)
• 240aa20 Drain connection after PoolManager redirect (#1817)
• 5777ec4 Detect GitHub Actions as continuous integration (#1840)
• 8e1fe6c Switch macOS CI to GitHub Actions (#1839)
• Additional commits viewable in compare view

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[dependabot-preview]

We've just been alerted that this update fixes a security vulnerability:

Sourced from The GitHub Security Advisory Database.

Uncontrolled Resource Consumption in urllib3

The _encode_invalid_chars function in util/url.py in the urllib3 library 1.25.2 through 1.25.7 for Python allows a denial of service (CPU consumption) because of an inefficient algorithm. The percent_encodings array contains all matches of percent encodings. It is not deduplicated. For a URL of length N, the size of percent_encodings may be up to O(N). The next step (normalize existing percent-encoded bytes) also takes up to O(N) for each step, so the total time is O(N^2). If percent_encodings were deduplicated, the time to compute _encode_invalid_chars would be O(kN), where k is at most 484 ((10+6*2)^2).

Affected versions: [">= 1.25.2, <= 1.25.7"]