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Non-constant-time SCIM token comparison in Zulip Server

Moderate
alexmv published GHSA-q5gx-377v-w76f Nov 16, 2022

Package

Zulip Server (Application)

Affected versions

5.0 through 5.6

Patched versions

5.7

Description

Impact

Zulip Server 5.0 through 5.6 checked SCIM bearer tokens using a comparator that did not run in constant time. For organizations with SCIM account management enabled, this bug theoretically allowed an attacker to steal the SCIM bearer token, and use it to read and update the Zulip organization’s user accounts. In practice, this vulnerability may not have been practical or exploitable.

Workarounds

Organizations where SCIM account management has not been enabled are not affected.

For more information

If you have any questions or comments about this advisory, you can discuss them on the developer community Zulip server, or email the Zulip security team.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

CVE ID

CVE-2022-41914

Weaknesses