CVE-2021-43791 : Zulip is an open source group chat application that combines real-time chat with

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.

Published 2021-12-02 01:15:07

Updated 2021-12-03 18:09:07

Source GitHub, Inc.

View at NVD, CVE.org

Products affected by CVE-2021-43791

Zulip » Zulip
Versions before (<) 4.8
cpe:2.3:a:zulip:zulip:*:*:*:*:*:*:*:*
Matching versions

Exploit prediction scoring system (EPSS) score for CVE-2021-43791

EPSS FAQ

0.19%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 41 %

Percentile, the proportion of vulnerabilities that are scored at or less

CVSS scores for CVE-2021-43791

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
5.0	MEDIUM	AV:N/AC:L/Au:N/C:N/I:P/A:N	10.0	2.9	NIST
Access Vector: Network Access Complexity: Low Authentication: None Confidentiality Impact: None Integrity Impact: Partial Availability Impact: None
5.3	MEDIUM	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N	3.9	1.4	NIST
Attack Vector: Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: None Integrity: Low Availability: None
6.5	MEDIUM	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N	3.9	2.5	GitHub, Inc.
Attack Vector: Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: Low Integrity: Low Availability: None

CWE ids for CVE-2021-43791

CWE-613 Insufficient Session Expiration

According to WASC, "Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization."

Assigned by: security-advisories@github.com (Primary)

References for CVE-2021-43791

https://github.com/zulip/zulip/commit/a014ef75a3a0ed7f24ebb157632ba58751e732c6

CVE-2021-43791: Validate confirmation keys in /accounts/register/ cod… · zulip/zulip@a014ef7 · GitHub
Patch;Third Party Advisory
https://github.com/zulip/zulip/security/advisories/GHSA-wj76-pcqr-mf9f

Ineffective expiration validation for invitation links · Advisory · zulip/zulip · GitHub
Third Party Advisory

Jump to

Vulnerability Details : CVE-2021-43791

Products affected by CVE-2021-43791

Exploit prediction scoring system (EPSS) score for CVE-2021-43791

CVSS scores for CVE-2021-43791

CWE ids for CVE-2021-43791

References for CVE-2021-43791