CVE-2017-14722

WordPress Core < 4.8.2 - Directory Traversal via Customizer

2017-09-19 00:00

Strategic Overview

Status: Patched in 3.7.22
Affected Core: WordPress 4.8
Affected Version: 3.7 – 4.8.1 · 13 branches
CVSS: 4.9Medium
Weakness type: CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVE: CVE-2017-14722

At a glance

CVE-2017-14722 is a medium-severity Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in the WordPress 4.8 WordPress release line, affecting 3.7 – 4.8.1 · 13 branches. It carries a CVSS score of 4.9 (reachable over the network; low attack complexity; high confidentiality impact). The issue is fixed in version 3.7.22; sites on affected versions should update now. Disclosed September 2017, reported by Weston Ruter.

Vulnerability Overview

Before version 4.8.2, WordPress allowed a Directory Traversal attack in the Customizer component via a crafted theme filename.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user. A successful exploit has high impact on confidentiality.

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

Reaching this weakness in WordPress 4.8 3.7 – 4.8.1 · 13 branches takes a caller who can reach the endpoint. Path traversal happens when user-controlled text is used to build a filesystem path without being constrained to an intended directory, so sequences like ../ walk the resolved path somewhere else.

Depending on the operation, it means reading files outside the intended folder — wp-config.php being the usual target — or writing to and deleting paths the web server can touch. For WordPress 4.8 the fix is 3.7.22: builds 3.7 – 4.8.1 · 13 branches are affected, anything from 3.7.22 onward is not.

Remediation

Update to one of the following versions, or a newer patched version: 3.7.22, 3.8.22, 3.9.20, 4.0.19, 4.1.19, 4.2.16, 4.3.12, 4.4.11, 4.5.10, 4.6.7, 4.7.6, 4.8.2

How does WordSec protect against this?

The attempt arrives as an ordinary request to WordPress 4.8: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: updating to 3.7.22 is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2017-14722 https://www.wordfence.com/threat-intel/vulnerabilities/id/bbe9eed9-9a96-47da-95fa-b942817a9d4f https://nvd.nist.gov/vuln/detail/CVE-2017-14722

Related records

Same weakness class

Other vulnerabilities in WordPress 4.8

CVSS Vector

4.9

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredHigh
User InteractionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityNone
AvailabilityNone

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