Improper Authentication in Atlassian Crowd

1) Improper Authentication

EUVDB-ID: #VU41121

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-18106

CWE-ID: CWE-287 - Improper Authentication

Exploit availability: No

Description

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

The identifier_hash for a session token in Atlassian Crowd before version 2.9.1 could potentially collide with an identifier_hash for another user or a user in a different directory, this allows remote attackers who can authenticate to Crowd or an application using Crowd for authentication to gain access to another user's session provided they can make their identifier hash collide with another user's session identifier hash.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Crowd: 2.9.0

External links

http://jira.atlassian.com/browse/CWD-5061

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.