Zulip Server up to 1.7.0 Invitation System User improper authentication

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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A vulnerability has been found in Zulip Server up to 1.7.0 and classified as critical. Affected by this vulnerability is some unknown functionality of the component Invitation System. The manipulation with an unknown input leads to a improper authentication vulnerability (User). The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In Zulip Server before 1.7.1, on a server with multiple realms, a vulnerability in the invitation system lets an authorized user of one realm on the server create a user account on any other realm.

The bug was discovered 11/23/2017. The weakness was presented 11/27/2017 (Website). The advisory is shared at blog.zulip.org. This vulnerability is known as CVE-2017-0910 since 11/30/2016. The attack can be launched remotely. A single authentication is required for exploitation. Neither technical details nor an exploit are publicly available.

The vulnerability was handled as a non-public zero-day exploit for at least 4 days. During that time the estimated underground price was around $0-$5k.

Upgrading to version 1.7.1 eliminates this vulnerability.






CPE 2.3info

CPE 2.2info


VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
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VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.4

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.8
NVD Vector: 🔍



VulDB Base Score: 🔍
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NVD Base Score: 🔍


Name: User
Class: Improper authentication / User
CWE: CWE-287
ATT&CK: Unknown

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍


Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍


Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Server 1.7.1
Patch: github.com


11/30/2016 🔍
11/23/2017 +358 days 🔍
11/27/2017 +4 days 🔍
11/27/2017 +0 days 🔍
11/28/2017 +1 days 🔍
01/16/2023 +1875 days 🔍


Advisory: 960d736e55cbb9386a68e4ee45f80581fd2a4e32
Status: Not defined
Confirmation: 🔍

CVE: CVE-2017-0910 (🔍)


Created: 11/28/2017 07:41 AM
Updated: 01/16/2023 12:32 PM
Changes: 11/28/2017 07:41 AM (59), 12/10/2019 07:21 PM (2), 01/16/2023 12:32 PM (5)
Complete: 🔍


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