CVE-2017-6816

WordPress Core < 4.7.3 - Arbitrary File Deletion

2017-03-06 00:00

Strategic Overview

Status: Patched in 3.7.19
Affected Core: WordPress 4.7
Affected Version: 3.7 – 4.7.2 · 12 branches
CVSS: 4.9Medium
Weakness type: CWE-863 · Incorrect Authorization
CVE: CVE-2017-6816

At a glance

CVE-2017-6816 is a medium-severity Incorrect Authorization vulnerability in the WordPress 4.7 WordPress release line, affecting 3.7 – 4.7.2 · 12 branches. It carries a CVSS score of 4.9 (reachable over the network; low attack complexity; high integrity impact). The issue is fixed in version 3.7.19; sites on affected versions should update now. Disclosed March 2017, reported by TrigInc.

Vulnerability Overview

In WordPress before 4.7.3 (wp-admin/plugins.php), unintended files can be deleted by administrators using the plugin deletion functionality.

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 integrity.

CWE-863: Incorrect Authorization

Reaching this weakness in WordPress 4.7 3.7 – 4.7.2 · 12 branches takes a caller who can reach the endpoint. Incorrect authorization means a permission check exists but evaluates the wrong thing, so it passes for callers it was meant to stop.

The action runs for users the code intended to exclude, with the same effect as having no check at all. For WordPress 4.7 the fix is 3.7.19: builds 3.7 – 4.7.2 · 12 branches are affected, anything from 3.7.19 onward is not.

Remediation

Update to one of the following versions, or a newer patched version: 3.7.19, 3.8.19, 3.9.17, 4.0.16, 4.1.16, 4.2.13, 4.3.9, 4.4.8, 4.5.7, 4.6.4, 4.7.3

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: updating to 3.7.19 is the step that ends it.

Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2017-6816 https://www.wordfence.com/threat-intel/vulnerabilities/id/a3779501-4ac7-4b76-8b2b-9852c6467f16 https://nvd.nist.gov/vuln/detail/CVE-2017-6816

Related records

Same weakness class

5.4CVE-2012-2402: WordPress Core < 3.3.2 Authorization BypassCVE-2012-2402

Other vulnerabilities in WordPress 4.7

CVSS Vector

4.9

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredHigh
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityHigh
AvailabilityNone

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