CVE-2023-32677Network attack vector

Unauthorized stream access via missing invitation permission check

Published May 19, 2023 · Updated Feb 12, 2025

Improper authorization in Zulip Server 1.9.0 through 6.1 allows remote authenticated users to grant invitees unauthorized stream access. The invite_users_backend function passed selected streams to do_invite_users without checking user_profile.can_subscribe_other_users(). Exploitation requires separate policies that permit invitations but restrict adding users to streams, and access remains limited to streams visible to the inviting user.

CVSS severity3.1
Low
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authorization in Zulip Server 1.9.0 through 6.1 allows remote authenticated users to grant invitees unauthorized stream access. The invite_users_backend function passed selected streams to do_invite_users without checking user_profile.can_subscribe_other_users(). Exploitation requires separate policies that permit invitations but restrict adding users to streams, and access remains limited to streams visible to the inviting user.

The record

CVE
CVE-2023-32677
Published
May 19, 2023
Updated
Feb 12, 2025
Vendor
Zulip
Product
Zulip
Classifications
CWE-862, T1098
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 19, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 12, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=> 1.9.0, < 6.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Zulip · Zulipversion=> 1.9.0, < 6.2

Published CVSS scores

3.1GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization
T1098Account Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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