Cyber Resilience

CVE-2022-21706

High

Published: 26 February 2022

Published
26 February 2022
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
EPSS Score 0.0012 30.7th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2022-21706 is a high-severity Improper Access Control (CWE-284) vulnerability in Zulip Zulip Server. Its CVSS base score is 7.2 (High).

Operationally, ranked at the 30.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Zulip is an open-source team collaboration tool with topic-based threading. Zulip Server version 2.0.0 and above are vulnerable to insufficient access control with multi-use invitations. A Zulip Server deployment which hosts multiple organizations is vulnerable to an attack where an…

more

invitation created in one organization (potentially as a role with elevated permissions) can be used to join any other organization. This bypasses any restrictions on required domains on users' email addresses, may be used to gain access to organizations which are only accessible by invitation, and may be used to gain access with elevated privileges. This issue has been patched in release 4.10. There are no known workarounds for this issue. ### Patches _Has the problem been patched? What versions should users upgrade to?_ ### Workarounds _Is there a way for users to fix or remediate the vulnerability without upgrading?_ ### References _Are there any links users can visit to find out more?_ ### For more information If you have any questions or comments about this advisory, you can discuss them on the [developer community Zulip server](https://zulip.com/developer-community/), or email the [Zulip security team](mailto:security@zulip.com).

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

zulip
zulip server
2.0.0 — 4.10.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-284 CWE-863

The access control policy and procedures directly mandate and enforce proper access control mechanisms across the organization.

addresses: CWE-284 CWE-863

Supervision and review of access control activities directly detects and remediates improper access configurations or usages.

addresses: CWE-284 CWE-863

Associating and retaining security attributes with data directly supports enforcement of access control decisions across storage, processing, and transmission.

addresses: CWE-284 CWE-863

Requiring prior authorization for each remote access type prevents improper access control over remote connections.

addresses: CWE-284 CWE-863

Requiring authorization of wireless access before allowing connections enforces proper access control for this access method.

addresses: CWE-284 CWE-863

Requiring authorization and configuration controls for mobile device connections directly enforces access control and prevents unauthorized devices from reaching organizational systems.

addresses: CWE-284 CWE-863

Defining account types, requiring approvals for creation, specifying authorizations, monitoring usage, and reviewing accounts directly prevents improper access control by ensuring only authorized accounts exist and are used.

addresses: CWE-284 CWE-863

Enforces rules governing access to the system and its data from external systems based on established trust relationships.

References