[Django] #37101: Vary header cache key collision from missing delimiter

[Django]

#37101: Vary header cache key collision from missing delimiter
-------------------------------------+-------------------------------------
Reporter: Jake Howard | Type: Bug
Status: new | Component: Core
| (Cache system)
Version: 6.0 | Severity: Normal
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
When a cached view varies on multiple headers, the values of those headers
are concatenated together in the cache key. There is no delimiter, meaning
the cache keys could overlap:

{{{
X-Region: US
X-Tenant: victim-corp
}}}

{{{

X-Region: U
X-Tenant: Svictim-corp
}}}

The above 2 examples would result in the same cache key, despite being
different values. Changes to the cache key should be made to ensure values
in this way don't collide.

----

This was previously reported to the Security Team by GeonHa. However,
because it requires in depth knowledge of the system, a lack of user
validation and similar values, it is not considered a vulnerability.
--
Ticket URL: <https://code.djangoproject.com/ticket/37101>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.

[Django]

#37101: Vary header cache key collision from missing delimiter
-------------------------------------+------------------------------------

Reporter: Jake Howard | Owner: (none)

Type: Bug | Status: new
Component: Core (Cache system) | Version: 6.0

Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted

Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+------------------------------------

Changes (by Sarah Boyce):

* stage: Unreviewed => Accepted

--
Ticket URL: <https://code.djangoproject.com/ticket/37101#comment:1>

[Django]

#37101: Vary header cache key collision from missing delimiter

-------------------------------------+-------------------------------------
Reporter: Jake Howard | Owner: gonas0919
Type: Bug | Status: assigned

Component: Core (Cache system) | Version: 6.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0

-------------------------------------+-------------------------------------
Changes (by gonas0919):

* owner: (none) => gonas0919
* status: new => assigned

--
Ticket URL: <https://code.djangoproject.com/ticket/37101#comment:2>

[Django]

#37101: Vary header cache key collision from missing delimiter

-------------------------------------+------------------------------------
Reporter: Jake Howard | Owner: gonas

Type: Bug | Status: assigned
Component: Core (Cache system) | Version: 6.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+------------------------------------

Comment (by Jason Judkins):

@Gonas Hey, are you still working on this? Happy to collaborate or take it
over if you've moved on.
--
Ticket URL: <https://code.djangoproject.com/ticket/37101#comment:3>

[Django]

#37101: Vary header cache key collision from missing delimiter
-------------------------------------+------------------------------------
Reporter: Jake Howard | Owner: gonas
Type: Bug | Status: assigned
Component: Core (Cache system) | Version: 6.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+------------------------------------

Comment (by Jacob Walls):

We're hoping to land a fix for this before the 6.1 beta (June 24), so if
we don't have a PR by early next week, I'll need to pick it up myself.
Happy for you to make a start, Jason.
--
Ticket URL: <https://code.djangoproject.com/ticket/37101#comment:4>

[Django]

#37101: Vary header cache key collision from missing delimiter

-------------------------------------+-------------------------------------
Reporter: Jake Howard | Owner: Jacob
| Walls

Type: Bug | Status: assigned
Component: Core (Cache system) | Version: 6.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0

-------------------------------------+-------------------------------------
Changes (by Jacob Walls):

* owner: gonas => Jacob Walls

--
Ticket URL: <https://code.djangoproject.com/ticket/37101#comment:5>

[Django]

#37101: Vary header cache key collision from missing delimiter
-------------------------------------+-------------------------------------
Reporter: Jake Howard | Owner: Jacob
| Walls
Type: Bug | Status: assigned
Component: Core (Cache system) | Version: 6.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted

Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Changes (by Jacob Walls):

* has_patch: 0 => 1

Comment:

[https://github.com/django/django/pull/21516 PR]
--
Ticket URL: <https://code.djangoproject.com/ticket/37101#comment:6>

[Django]

#37101: Vary header cache key collision from missing delimiter
-------------------------------------+-------------------------------------
Reporter: Jake Howard | Owner: Jacob
| Walls
Type: Bug | Status: assigned
Component: Core (Cache system) | Version: 6.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 1

Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by Natalia Bidart):

* needs_better_patch: 0 => 1

--
Ticket URL: <https://code.djangoproject.com/ticket/37101#comment:7>

[Django]

#37101: Vary header cache key collision from missing delimiter
-------------------------------------+-------------------------------------
Reporter: Jake Howard | Owner: Jacob
| Walls
Type: Bug | Status: assigned
Component: Core (Cache system) | Version: 6.0
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 1 | Needs documentation: 0

Needs tests: 0 | Patch needs improvement: 0

Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by Jacob Walls):

* needs_better_patch: 1 => 0

--
Ticket URL: <https://code.djangoproject.com/ticket/37101#comment:8>

[Django]

#37101: Vary header cache key collision from missing delimiter
-------------------------------------+-------------------------------------
Reporter: Jake Howard | Owner: Jacob
| Walls
Type: Bug | Status: assigned
Component: Core (Cache system) | Version: 6.0
Severity: Normal | Resolution:

Keywords: | Triage Stage: Ready for
| checkin

Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by Natalia Bidart):

* stage: Accepted => Ready for checkin

--
Ticket URL: <https://code.djangoproject.com/ticket/37101#comment:9>

[Django]

#37101: Vary header cache key collision from missing delimiter
-------------------------------------+-------------------------------------
Reporter: Jake Howard | Owner: Jacob
| Walls

Type: Bug | Status: closed

Component: Core (Cache system) | Version: 6.0

Severity: Normal | Resolution: fixed

Keywords: | Triage Stage: Ready for
| checkin
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by Jacob Walls <jacobtylerwalls@…>):

In [changeset:"02f94d2a899b6573f90dee5417afb8a763ee7f25" 02f94d2]:
{{{#!CommitTicketReference repository=""
revision="02f94d2a899b6573f90dee5417afb8a763ee7f25"
Refs #37101, #37174 -- Added release note for cache misses when varying on
arguments.

Thanks Natalia Bidart for the review.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/37101#comment:11>

[Django]

#37101: Vary header cache key collision from missing delimiter
-------------------------------------+-------------------------------------
Reporter: Jake Howard | Owner: Jacob
| Walls
Type: Bug | Status: closed
Component: Core (Cache system) | Version: 6.0
Severity: Normal | Resolution: fixed
Keywords: | Triage Stage: Ready for
| checkin
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by Jacob Walls <jacobtylerwalls@…>):

* resolution: => fixed
* status: assigned => closed

Comment:

In [changeset:"65acb3cc2e76c238f5aee38d22626d92171a2f7c" 65acb3cc]:
{{{#!CommitTicketReference repository=""
revision="65acb3cc2e76c238f5aee38d22626d92171a2f7c"
Fixed #37101 -- Used netstring delimiter between vary on headers for
cached pages.

This prevents collisions between header values that concatenate to the
same thing.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/37101#comment:10>

[Django]

#37101: Vary header cache key collision from missing delimiter
-------------------------------------+-------------------------------------
Reporter: Jake Howard | Owner: Jacob
| Walls
Type: Bug | Status: closed
Component: Core (Cache system) | Version: 6.0
Severity: Normal | Resolution: fixed
Keywords: | Triage Stage: Ready for
| checkin
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by Jacob Walls <jacobtylerwalls@…>):

In [changeset:"8ae64fc040f1da7737f389a0d815808ffade2bd8" 8ae64fc]:
{{{#!CommitTicketReference repository=""
revision="8ae64fc040f1da7737f389a0d815808ffade2bd8"
[6.1.x] Fixed #37101 -- Used netstring delimiter between vary on headers

for cached pages.

This prevents collisions between header values that concatenate to the
same thing.

Backport of 65acb3cc2e76c238f5aee38d22626d92171a2f7c from main.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/37101#comment:12>

[Django]

#37101: Vary header cache key collision from missing delimiter
-------------------------------------+-------------------------------------
Reporter: Jake Howard | Owner: Jacob
| Walls
Type: Bug | Status: closed
Component: Core (Cache system) | Version: 6.0
Severity: Normal | Resolution: fixed
Keywords: | Triage Stage: Ready for
| checkin
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Comment (by Jacob Walls <jacobtylerwalls@…>):

In [changeset:"e4cda2e5dd314bb5f9a15b6b4d74a14a87ae1dec" e4cda2e]:
{{{#!CommitTicketReference repository=""
revision="e4cda2e5dd314bb5f9a15b6b4d74a14a87ae1dec"
[6.1.x] Refs #37101, #37174 -- Added release note for cache misses when

varying on arguments.

Thanks Natalia Bidart for the review.

Backport of 02f94d2a899b6573f90dee5417afb8a763ee7f25 from main.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/37101#comment:13>