What’s Vulnerable › Vulnerabilities

CVE-2021-21354: Open redirect in pollbot

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-03-08 · updated 2026-06-17
• Weakness: CWE-601

Description

Pollbot is open source software which "frees its human masters from the toilsome task of polling for the state of things during the Firefox release process." In Pollbot before version 1.4.4 there is an open redirection vulnerability in the path of "https://pollbot.services.mozilla.com/". An attacker can redirect anyone to malicious sites. To Reproduce type in this URL: "https://pollbot.services.mozilla.com//evil.com/". Affected versions will redirect to that website when you inject a payload like "//evil.com/". This is fixed in version 1.4.4.

Affected products

• mozilla/pollbot: before 1.4.4 — fixed in 1.4.4

How to fix

Upgrade to a fixed version: mozilla/pollbot 1.4.4. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1694684
• https://cheatsheetseries.owasp.org/cheatsheets/Unvalidated_Redirects_and_Forwards_Cheat_Sheet.html
• https://github.com/mozilla/PollBot/commit/6db74a4fcbff258c7cdf51a6ff0724fc10c485e5
• https://github.com/mozilla/PollBot/pull/333
• https://github.com/mozilla/PollBot/releases/tag/v1.4.4
• https://github.com/mozilla/PollBot/security/advisories/GHSA-jhgx-wmq8-jc24
• https://bugzilla.mozilla.org/show_bug.cgi?id=1694684
• https://cheatsheetseries.owasp.org/cheatsheets/Unvalidated_Redirects_and_Forwards_Cheat_Sheet.html
• https://github.com/mozilla/PollBot/commit/6db74a4fcbff258c7cdf51a6ff0724fc10c485e5
• https://github.com/mozilla/PollBot/pull/333
• https://github.com/mozilla/PollBot/releases/tag/v1.4.4
• https://github.com/mozilla/PollBot/security/advisories/GHSA-jhgx-wmq8-jc24

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