Two vulnerabilities in b2evolution

Published: 2017-01-16

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2017-5494 CVE-2017-5480
CWE-ID	CWE-79 CWE-22
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	b2evolution Web applications / CMS
Vendor	b2evolution.net

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Stored cross-site scripting

EUVDB-ID: #VU4660

Risk: Low

CVSSv3.1: 5.6 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-5494

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

Exploit availability: No

Description

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 when uploading .swf files for avatar and comments. A remote authenticated attacker can upload malicious .swf file, containing arbitrary JavaScript code and execute it in user's browser in context of vulnerable website, when the victim visits a page with uploaded file.

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.

Mitigation

Install update from vendor's GIT repository.

Vulnerable software versions

b2evolution: 6.8.1 - 6.8.3

External links

http://github.com/b2evolution/b2evolution/issues/34
http://github.com/b2evolution/b2evolution/commit/261dbd5b294e707af766691e65a177a290314a6e

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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

2) Directory traversal

EUVDB-ID: #VU4748

Risk: Medium

CVSSv3.1: 6.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-5480

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Exploit availability: No

Description

The vulnerability allows a remote attacker to view arbitrary files on vulnerable system.

The vulnerability exists due to insufficient sanitization of user-supplied data passed "fm_selected" array parameter in "inc/files/files.ctrl.php" script. A remote authenticated attacker can use directory traversal sequences (e.g. ../) to view contents of arbitrary files on vulnerable system.

Successful exploitation of the vulnerability may allow an attacker to obtain sensitive ad system information.