Nautobot's BANNER_* configuration can be used to inject arbitrary HTML content into Nautobot pages
Date: 2024-05
Affected: pip/nautobot, pip/nautobot
Attack vector: xss
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2024-34707
CWE: CWE-79
CVSS: 7.5 (CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:H/A:L)

### Impact A Nautobot user with admin privileges can modify the `BANNER_TOP`, `BANNER_BOTTOM`, and `BANNER_LOGIN` configuration settings via the `/admin/constance/config/` endpoint. Normally these settings are used to provide custom banner text at the top and bottom of all Nautobot web pages (or specifically on the login page in the case of `BANNER_LOGIN`) but it was reported that an admin user can make use of these settings to inject arbitrary HTML, potentially exposing Nautobot users to security issues such as cross-site scripting (stored XSS). ### Patches _Has the problem been patched? What versions should users upgrade to?_ Patches will be released as part of Nautobot 1.6.22 and 2.2.4. ### Workarounds _Is there a way for users to fix or remediate the vulnerability without upgrading?_ As [described in the Nautobot documentation](https://docs.nautobot.com/projects/core/en/stable/user-guide/administration/configuration/optional-settings/#administratively-configurable-settings), these settings are only configurable through the admin UI of Nautobot if they are *not* explicitly set to some non-empty value in the `nautobot_config.py` or equivalent Nautobot configuration file. Therefore, adding the following configuration to said file completely mitigates this vulnerability in both Nautobot 1.x and 2.x: ```python BANNER_LOGIN = " " BANNER_TOP = " " BANNER_BOTTOM = " " ``` or alternately (Nautobot 2.x only), if those variables are not defined explicitly in your configuratio


Mitigations:

Architectural layers (MAESTRO):