SB2017012324 - Path traversal in b2evolution.net b2evolution

Description

This security bulletin contains information about 1 vulnerability.

1) Path traversal (CVE-ID: CVE-2017-5539)

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

CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]

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

The patch for directory traversal (CVE-2017-5480) in b2evolution version 6.8.4-stable has a bypass vulnerability. An attacker can use ../ to bypass the filter rule. Then, this attacker can exploit this vulnerability to delete or read any files on the server. It can also be used to determine whether a file exists.

Remediation

Install update from vendor's website.

References

• http://b2evolution.net/downloads/6-8-5
• http://www.securityfocus.com/bid/95700
• https://github.com/b2evolution/b2evolution/commit/e35f7c195d8c1103d2d981a48cda5ab45ecac48a
• https://github.com/b2evolution/b2evolution/issues/36