Changes to 2.4.6 url encoding, trigger certain WaF rules

[toonvd]

Preconditions and environment

• 2.4.6
• https://github.com/magento/magento2/commit/5c8ef9d3abbdec1216422eed8d76b8936c945cb7
• A file ending or starting with a tilde, is very often a temp file. Some WaFs, tend to block these requests as it could mean an attempt to abuse old temp files for fetching information.

Steps to reproduce

Check URLs in checkout for example

Expected result

Another character that does not suggest an attempt to abuse temp files should be used.

Actual result

A tilde is used and often ends up at the start or the end of the path

Additional information

No response

Release note

No response

Triage and priority

• [ ] Severity: S0 - Affects critical data or functionality and leaves users without workaround.
• [ ] Severity: S1 - Affects critical data or functionality and forces users to employ a workaround.
• [X] Severity: S2 - Affects non-critical data or functionality and forces users to employ a workaround.
• [ ] Severity: S3 - Affects non-critical data or functionality and does not force users to employ a workaround.
• [ ] Severity: S4 - Affects aesthetics, professional look and feel, “quality” or “usability”.

[m2-assistant[bot]]

Hi @toonvd. Thank you for your report. To speed up processing of this issue, make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, Add a comment to the issue:

• @magento give me 2.4-develop instance - upcoming 2.4.x release
• For more details, review the Magento Contributor Assistant documentation.
• Add a comment to assign the issue: @magento I am working on this

• To learn more about issue processing workflow, refer to the Code Contributions.

  Join Magento Community Engineering Slack and ask your questions in #github channel. :warning: According to the Magento Contribution requirements, all issues must go through the Community Contributions Triage process. Community Contributions Triage is a public meeting. :clock10: You can find the schedule on the Magento Community Calendar page. :telephone_receiver: The triage of issues happens in the queue order. If you want to speed up the delivery of your contribution, join the Community Contributions Triage session to discuss the appropriate ticket.

[m2-assistant[bot]]

Hi @engcom-Bravo. Thank you for working on this issue. In order to make sure that issue has enough information and ready for development, please read and check the following instruction: :point_down:

• [ ] 1. Verify that issue has all the required information. (Preconditions, Steps to reproduce, Expected result, Actual result).
• [ ] 2. Verify that issue has a meaningful description and provides enough information to reproduce the issue.
• [ ] 3. Add Area: XXXXX label to the ticket, indicating the functional areas it may be related to.
• [ ] 4. Verify that the issue is reproducible on 2.4-develop branch
  Details

  - Add the comment @magento give me 2.4-develop instance to deploy test instance on Magento infrastructure.
  - If the issue is reproducible on 2.4-develop branch, please, add the label Reproduced on 2.4.x.
  - If the issue is not reproducible, add your comment that issue is not reproducible and close the issue and stop verification process here!
• [ ] 5. Add label Issue: Confirmed once verification is complete.
• [ ] 6. Make sure that automatic system confirms that report has been added to the backlog.

[engcom-Bravo]

Hi @toonvd,

Thank you for reporting and collaboration.

Could you please elaborate the steps to reproduce in order to reproduce the issue and also if possible please provide us screenshots it will helps us to proceed further.

Thanks.

[toonvd]

Hi

The commit and explanation should be more than enough. Taking screenshots of a blocked request really doesn't add any value.

Here's an example of a link:

https://toonistesting.nl/customer/account/login/referer/aHR0cHM6Ly93d3cucHNmb29kYW5kbGlmZXN0eWxlLm5sL2N1c3RvbWVyL2FjT291bnQvaW5kZBg~

As you can see, this link ends with a tilde because of the replace function in the referenced commit. Files starting and ending with a tilde are temp files for many editors + almost all Windows applications. Hence it triggers blocks / false positives.

[m2-assistant[bot]]

Hi @engcom-November. Thank you for working on this issue. In order to make sure that issue has enough information and ready for development, please read and check the following instruction: :point_down:

• [ ] 1. Verify that issue has all the required information. (Preconditions, Steps to reproduce, Expected result, Actual result).
• [ ] 2. Verify that issue has a meaningful description and provides enough information to reproduce the issue.
• [ ] 3. Add Area: XXXXX label to the ticket, indicating the functional areas it may be related to.
• [ ] 4. Verify that the issue is reproducible on 2.4-develop branch
  Details

  - Add the comment @magento give me 2.4-develop instance to deploy test instance on Magento infrastructure.
  - If the issue is reproducible on 2.4-develop branch, please, add the label Reproduced on 2.4.x.
  - If the issue is not reproducible, add your comment that issue is not reproducible and close the issue and stop verification process here!
• [ ] 5. Add label Issue: Confirmed once verification is complete.
• [ ] 6. Make sure that automatic system confirms that report has been added to the backlog.

[engcom-November]

@magento give me 2.4-develop instance

[magento-deployment-service[bot]]

Hi @engcom-November. Thank you for your request. I'm working on Magento instance for you.

[magento-deployment-service[bot]]

Hi @engcom-November, here is your Magento Instance: https://95565bd0b05b1e00f489c50571316078.instances-prod.magento-community.engineering Admin access: https://95565bd0b05b1e00f489c50571316078.instances-prod.magento-community.engineering/admin_3edd Login: d74f0bd7 Password: 9514622e0087

[engcom-November]

Hello @toonvd,

Thank you for the report!

According to RFC 3986 tilde is a unreserved character and can be used in the url. But as the url is getting blocked, could you try to reconfigure the WAF to allow tilde character.

Thank you.

[toonvd]

Hi

This is not about RFC but about common sense. A lot of enterprise WaFs block or alert on tilde by default. (Barracuda, Fortinet, several Modsec rulesets,...). The reason for this is an old IIS vulnerability, Windows using tilde for temp files and other applications like text editors (joe, gedit,...) using tildes for temp files.

Gitlab also fixed this 3 years ago because of this exact reason. https://gitlab.com/gitlab-org/gitlab/-/issues/22648

[engcom-November]

Hello @toonvd,

Thank you for the quick response!

In this case, as you mentioned tilde might cause false postive in some of the WAF's. So this issue can be confirmed.

Thank you.

[github-jira-sync-bot]

:white_check_mark: Jira issue https://jira.corp.adobe.com/browse/AC-10723 is successfully created for this GitHub issue.

[m2-assistant[bot]]

:white_check_mark: Confirmed by @engcom-November. Thank you for verifying the issue.
Issue Available: @engcom-November, You will be automatically unassigned. Contributors/Maintainers can claim this issue to continue. To reclaim and continue work, reassign the ticket to yourself.