CVE-2023-47642Network attack vector

Authenticated stream metadata disclosure via stale subscription authorization

Published Nov 16, 2023 · Updated Aug 29, 2024

Authorization bypass in Zulip Server 1.3.0 through 7.4 allows remote authenticated users to read restricted stream metadata via its API. Event-state construction classified previously subscribed users as never subscribed and kept serializing full stream data instead of an access-limited unsubscribed record. An active organization account and prior stream subscription are required; exposed fields include the stream name, description, settings, and incoming-email address.

CVSS severity4.3
Medium
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in Zulip Server 1.3.0 through 7.4 allows remote authenticated users to read restricted stream metadata via its API. Event-state construction classified previously subscribed users as never subscribed and kept serializing full stream data instead of an access-limited unsubscribed record. An active organization account and prior stream subscription are required; exposed fields include the stream name, description, settings, and incoming-email address.

The record

CVE
CVE-2023-47642
Published
Nov 16, 2023
Updated
Aug 29, 2024
Vendor
Zulip
Product
Zulip
Classifications
CWE-200, T1213
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 16, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 29, 2024Record 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=>= 1.3.0, < 7.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Zulip · Zulipversion=>= 1.3.0, < 7.5

Published CVSS scores

4.3GitHub CNACVSS:3.1/AV:N/AC:L/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-200Exposure of Sensitive Information to an Unauthorized Actor
T1213Data from Information Repositories

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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