CVE-2017-0896 - Missing Authorization

Severity

40%

Complexity

80%

Confidentiality

48%

Zulip Server 1.5.1 and below suffer from an error in the implementation of the invite_by_admins_only setting in the Zulip group chat application server that allowed an authenticated user to invite other users to join a Zulip organization even if the organization was configured to prevent this.

Zulip Server 1.5.1 and below suffer from an error in the implementation of the invite_by_admins_only setting in the Zulip group chat application server that allowed an authenticated user to invite other users to join a Zulip organization even if the organization was configured to prevent this.

CVSS 3.0 Base Score 6.5. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N).

CVSS 2.0 Base Score 4. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (AV:N/AC:L/Au:S/C:N/I:P/A:N).

Demo Examples

Missing Authorization

CWE-862

This function runs an arbitrary SQL query on a given database, returning the result of the query.


               
$employeeRecord = runEmployeeQuery('EmployeeDB',$_GET['EmployeeName']);
return $preparedStatement->fetchAll();//Use a prepared statement to avoid CWE-89
/.../

While this code is careful to avoid SQL Injection, the function does not confirm the user sending the query is authorized to do so. An attacker may be able to obtain sensitive employee information from the database.

Missing Authorization

CWE-862

The following program could be part of a bulletin board system that allows users to send private messages to each other. This program intends to authenticate the user before deciding whether a private message should be displayed. Assume that LookupMessageObject() ensures that the $id argument is numeric, constructs a filename based on that id, and reads the message details from that file. Also assume that the program stores all private messages for all users in the same directory.


               
DisplayPrivateMessage($id);
print "Body: " . encodeHTML($Message->{body}) . "\n";
# For purposes of this example, assume that CWE-309 and# CWE-523 do not apply.
ExitError("invalid username or password");

While the program properly exits if authentication fails, it does not ensure that the message is addressed to the user. As a result, an authenticated attacker could provide any arbitrary identifier and read private messages that were intended for other users.

One way to avoid this problem would be to ensure that the "to" field in the message object matches the username of the authenticated user.

Overview

Type

Zulip Server

First reported 7 years ago

2017-06-02 17:29:00

Last updated 5 years ago

2019-10-03 00:03:00

Affected Software

Zulip Server 1.3.0

1.3.0

Zulip Server 1.3.1

1.3.1

Zulip Server 1.3.2

1.3.2

Zulip Server 1.3.3

1.3.3

Zulip Server 1.3.4

1.3.4

Zulip Server 1.3.6

1.3.6

Zulip Server 1.3.7

1.3.7

Zulip Server 1.3.8

1.3.8

Zulip Server 1.3.9

1.3.9

Zulip Server 1.3.10

1.3.10

Zulip Server 1.3.11

1.3.11

Zulip Server 1.3.12

1.3.12

Zulip Server 1.3.13

1.3.13

Zulip Server 1.4.0

1.4.0

Zulip Server 1.4.1

1.4.1

Zulip Server 1.4.2

1.4.2

Zulip Server 1.4.3

1.4.3

Zulip Server 1.5.0

1.5.0

Zulip Server 1.5.1

1.5.1

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