CVE-2021-43791

Ineffective expiration validation for invitation links in Zulip

Description

Zulip is an open source group chat application that combines real-time chat with threaded conversations. In affected versions expiration dates on the confirmation objects associated with email invitations were not enforced properly in the new account registration flow. A confirmation link takes a user to the check_prereg_key_and_redirect endpoint, before getting redirected to POST to /accounts/register/. The problem was that validation was happening in the check_prereg_key_and_redirect part and not in /accounts/register/ - meaning that one could submit an expired confirmation key and be able to register. The issue is fixed in Zulip 4.8. There are no known workarounds and users are advised to upgrade as soon as possible.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.18%
Third-Party Advisory github.com Third-Party Advisory github.com
Affected: zulip zulip
Published at:
Updated at:

References

Link Tags
https://github.com/zulip/zulip/security/advisories/GHSA-wj76-pcqr-mf9f third party advisory
https://github.com/zulip/zulip/commit/a014ef75a3a0ed7f24ebb157632ba58751e732c6 third party advisory patch

Frequently Asked Questions

What is the severity of CVE-2021-43791?
CVE-2021-43791 has been scored as a medium severity vulnerability.
How to fix CVE-2021-43791?
To fix CVE-2021-43791, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-43791 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-43791 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-43791?
CVE-2021-43791 affects zulip zulip.
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