Fix failure to strip Authorization header on HTTP downgrade

Description

Impact

Authorization headers on requests are sensitive information. On making a request using the https scheme to a server which responds with a redirect to a URI with the http scheme, we should not forward the Authorization header on. This is much the same as to how we don't forward on the header if the host changes. Prior to this fix, https to http downgrades did not result in the Authorization header being removed, only changes to the host.

Patches

Affected Guzzle 7 users should upgrade to Guzzle 7.4.4 as soon as possible. Affected users using any earlier series of Guzzle should upgrade to Guzzle 6.5.7 or 7.4.4.

Workarounds

An alternative approach would be to use your own redirect middleware, rather than ours, if you are unable to upgrade. If you do not require or expect redirects to be followed, one should simply disable redirects all together.

References

For more information

If you have any questions or comments about this advisory, please get in touch with us in #guzzle on the PHP HTTP Slack. Do not report additional security advisories in that public channel, however - please follow our vulnerability reporting process.

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2022-06-09 23:47:23 UTC
Updated
2023-07-24 19:33:44 UTC
GitHub reviewed
2022-06-09 23:47:23 UTC
NVD published
2022-06-09

EPSS Score

Score Percentile
1.45% 80.52%

CVSS Scores

Base score Version Severity Vector
7.5 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

CWEs

CWE id Name
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
CWE-212 Improper Removal of Sensitive Information Before Storage or Transfer
CWE-863 Incorrect Authorization

Credits

  • GrahamCampbell (analyst)

Affected packages (2)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
composer guzzlehttp/guzzle >= 7.0.0, < 7.4.4 7.4.4
composer guzzlehttp/guzzle >= 4.0.0, < 6.5.7 6.5.7

References

cvelogic Threat Intelligence