Sidekiq is simple, efficient background processing for Ruby. Sidekiq is reflected XSS vulnerability. The value of substr parameter is reflected in the response without any encoding, allowing an attacker to inject Javascript code into the response of the application. An attacker could exploit it to target users of the Sidekiq Web UI. Moreover, if other applications are deployed on the same domain or website as Sidekiq, users of those applications could also be affected, leading to a broader scope of compromise. Potentially compromising their accounts, forcing the users to perform sensitive actions, stealing sensitive data, performing CORS attacks, defacement of the web application, etc. This issue has been patched in version 7.2.4.

sidekiq-unique-jobs is an open source project which prevents simultaneous Sidekiq jobs with the same unique arguments to run. Specially crafted GET request parameters handled by any of the following endpoints of sidekiq-unique-jobs' "admin" web UI, allow a super-user attacker, or an unwitting, but authorized, victim, who has received a disguised / crafted link, to successfully execute malicious code, which could potentially steal cookies, session data, or local storage data from the app the sidekiq-unique-jobs web UI is mounted in. 1. `/changelogs`, 2. `/locks` or 3. `/expiring_locks`. This issue has been addressed in versions 7.1.33 and 8.0.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Versions of the package sidekiq before 7.1.3 are vulnerable to Denial of Service (DoS) due to insufficient checks in the dashboard-charts.js file. An attacker can exploit this vulnerability by manipulating the localStorage value which will cause excessive polling requests.

Cross-site Scripting (XSS) - Reflected in GitHub repository sidekiq/sidekiq prior to 7.0.8.

In api.rb in Sidekiq before 5.2.10 and 6.4.0, there is no limit on the number of days when requesting stats for the graph. This overloads the system, affecting the Web UI, and makes it unavailable to users.

Sidekiq through 5.1.3 and 6.x through 6.2.0 allows XSS via the queue name of the live-poll feature when Internet Explorer is used.