SB2020082625 - Multiple vulnerabilities in Zulip Server

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Main Vulnerability Database SB2020082625

SB2020082625 - Multiple vulnerabilities in Zulip Server

Published: August 26, 2020

Security Bulletin ID SB2020082625
CSH Severity
High
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Information disclosure

Breakdown by Severity

High 25% Medium 50% Low 25%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 vulnerabilities.


1) Cross-site scripting (CVE-ID: CVE-2020-12759)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear


The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data passed via the Dropbox webhook. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.


2) Input validation error (CVE-ID: CVE-2020-14194)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote non-authenticated attacker to read and manipulate data.

Zulip Server before 2.1.5 allows reverse tabnapping via a topic header link.


3) Improper access control (CVE-ID: CVE-2020-14215)

CWE-ID: CWE-284 - Improper Access Control

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to gain unauthorized access to sensitive information.

The vulnerability exists due to improper access restrictions. A remote attacker can send a specially crafted request and gain unauthorized access to the affected application.


4) Improper Neutralization of Special Elements in Output Used by a Downstream Component (CVE-ID: CVE-2020-15070)

CWE-ID: CWE-74 - Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote authenticated user to execute arbitrary code.

Zulip Server 2.x before 2.1.7 allows eval injection if a privileged attacker were able to write directly to the postgres database, and chose to write a crafted custom profile field value.


Remediation

Install update from vendor's website.

References