What is the CVSS score of CVE-2023-22735?

CVE-2023-22735 has a CVSS 3.1 base score of 4.6 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N. EPSS exploitation probability: 0.5%.

Is there a patch available for CVE-2023-22735?

Yes, a patch is available for CVE-2023-22735. Update the affected software to the latest version immediately.

Zulip Server CVE-2023-22735

MEDIUM

Interpretation Conflict (CWE-436)

2023-02-07 security-advisories@github.com

Information Disclosure Zulip Server

4.6

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

4.6 MEDIUM

AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

CVE Published

Feb 07, 2023 - 19:15 nvd

MEDIUM 4.6

DescriptionNVD

Zulip is an open-source team collaboration tool. In versions of zulip prior to commit 2f6c5a8 but after commit 04cf68b users could upload files with arbitrary Content-Type which would be served from the Zulip hostname with Content-Disposition: inline and no Content-Security-Policy header, allowing them to trick other users into executing arbitrary Javascript in the context of the Zulip application. Among other things, this enables session theft. Only deployments which use the S3 storage (not the local-disk storage) are affected, and only deployments which deployed commit 04cf68b45ebb5c03247a0d6453e35ffc175d55da, which has only been in main, not any numbered release. Users affected should upgrade from main again to deploy this fix. Switching from S3 storage to the local-disk storage would nominally mitigate this, but is likely more involved than upgrading to the latest main which addresses the issue.

AnalysisAI

Zulip is an open-source team collaboration tool. Rated medium severity (CVSS 4.6), this vulnerability is remotely exploitable, low attack complexity.

Technical ContextAI

This vulnerability is classified under CWE-436. Zulip is an open-source team collaboration tool. In versions of zulip prior to commit 2f6c5a8 but after commit 04cf68b users could upload files with arbitrary Content-Type which would be served from the Zulip hostname with Content-Disposition: inline and no Content-Security-Policy header, allowing them to trick other users into executing arbitrary Javascript in the context of the Zulip application. Among other things, this enables session theft. Only deployments which use the S3 storage (not the local-disk storage) are affected, and only deployments which deployed commit 04cf68b45ebb5c03247a0d6453e35ffc175d55da, which has only been in main, not any numbered release. Users affected should upgrade from main again to deploy this fix. Switching from S3 storage to the local-disk storage would nominally mitigate this, but is likely more involved than upgrading to the latest main which addresses the issue. Affected products include: Zulip Zulip Server.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.