CVE-2021-30477

Severity Score

4.3

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

An issue was discovered in Zulip Server before 3.4. A bug in the implementation of replies to messages sent by outgoing webhooks to private streams meant that an outgoing webhook bot could be used to send messages to private streams that the user was not intended to be able to send messages to.

Se detectó un problema en Zulip Server versiones anteriores a 3.4. Un bug en la implementación de las respuestas a los mensajes enviados por webhooks salientes a transmisiones privadas significaba que un bot webhook saliente podía usarse para enviar mensajes a transmisiones privadas a las que el usuario no tenía la intención de poder enviar mensajes

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Attack Vector

Network

Attack Complexity

Low

Authentication

Single

Confidentiality

None

Integrity

Partial

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-04-09 CVE Reserved
2021-04-14 CVE Published
2024-08-03 CVE Updated
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (1)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://blog.zulip.com/2021/04/14/zulip-server-3-4	2022-07-12

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Zulip Search vendor "Zulip"		Zulip Server Search vendor "Zulip" for product "Zulip Server"				< 3.4 Search vendor "Zulip" for product "Zulip Server" and version " < 3.4"		-		Affected