Vulnerability · Published Dec 2, 2021 · Assigned by GitHub_M

CVE-2021-43791Ineffective expiration validation for invitation links in Zulip

Medium 6.5

In plain English

A medium-severity security flaw in zulip from zulip. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities).

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.7%top 48.1% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
zulip	zulip	< 4.8

Weakness: CWE-613 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References

https://github.com/zulip/zulip/security/advisories/GHSA-wj76-pcqr-mf9f x_refsource_CONFIRM
https://github.com/zulip/zulip/commit/a014ef75a3a0ed7f24ebb157632ba58751e732c6 x_refsource_MISC