CVE-2017-18553

Ad Buttons <= 2.3.1 - Cross-Site Request Forgery to Cross-Site Scripting

2015-05-08 00:00

Strategic Overview

Status: Patched in 2.3.2
Affected Plugin: Ad Buttons
Affected Version: < 2.3.2
CVSS: 6.1Medium
Weakness type: CWE-352 · Cross-Site Request Forgery (CSRF)
CVE: CVE-2017-18553

At a glance

CVE-2017-18553 is a medium-severity Cross-Site Request Forgery (CSRF) vulnerability in the Ad Buttons WordPress plugin, affecting versions < 2.3.2. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 2.3.2; sites on affected versions should update now. Disclosed May 2015, reported by Kaustubh G. Padwad.

Vulnerability Overview

The Ad Buttons plugin for WordPress is vulnerable to Cross-Site Scripting via Cross-Site Request Forgery via the ‘ab_yahurl’ parameter in versions up to, and including, 2.3.1 due to insufficient input sanitization and output escaping in addition to missing nonce protection. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

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 privileges on the target site.

CWE-352: Cross-Site Request Forgery (CSRF)

Ad Buttons < 2.3.2 carries this weakness at ab_yahurl, and reaching it takes a caller who can reach the endpoint. Cross-site request forgery abuses the fact that browsers attach a victim's cookies to any request, so a state-changing action that only checks who you are, not whether you meant to act, can be triggered from another site.

An attacker who gets a logged-in user to load a crafted page can perform that action as them, with the impact scaling to whatever the victim's role is allowed to do. For Ad Buttons the fix is 2.3.2: builds < 2.3.2 are affected, anything from 2.3.2 onward is not.

Remediation

Update to version 2.3.2, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Ad Buttons: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Ad Buttons 2.3.2 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2017-18553 https://www.wordfence.com/threat-intel/vulnerabilities/id/d5f36574-b4d0-4b67-baea-f5ef5e6618d1 https://nvd.nist.gov/vuln/detail/CVE-2017-18553

CVSS Vector

6.1

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

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