CVE-2017-18559

cformsII <= 14.13.2 - Cross-Site Scripting

2017-04-28 00:00

Strategic Overview

Status: Patched in 14.13.3
Affected Plugin: cformsII
Affected Version: <= 14.13.2
CVSS: 6.1Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2017-18559

At a glance

CVE-2017-18559 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the cformsII WordPress plugin, affecting versions <= 14.13.2. 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 14.13.3; sites on affected versions should update now. Disclosed April 2017.

Vulnerability Overview

The cformsII plugin for WordPress is vulnerable to Cross-Site Scripting in versions up to, and including, 14.13.2 due to insufficient input sanitization and output escaping on the 'switchform', 'pickform', and 'noSub' parameters. This makes it possible for attackers to inject arbitrary web scripts that execute in a victim's browser.

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

cformsII <= 14.13.2 carries this weakness at switchform, and reaching it takes a caller who can reach the endpoint. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For cformsII the fix is 14.13.3: builds <= 14.13.2 are affected, anything from 14.13.3 onward is not.

Remediation

Update to version 14.13.3, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to cformsII: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: cformsII 14.13.3 closes this, and updating the plugin is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2017-18559 https://www.wordfence.com/threat-intel/vulnerabilities/id/ab3ea93a-521a-45af-ac67-9f4417f3db59 https://nvd.nist.gov/vuln/detail/CVE-2017-18559

Related records

Same weakness class

Other vulnerabilities in cformsII

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

This record contains material that is subject to copyright

CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.

https://www.cve.org/Legal/TermsOfUse

Defiant hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute this software vulnerability information. Any copy of the software vulnerability information you make for such purposes is authorized provided that you include a hyperlink to this vulnerability record and reproduce Defiant's copyright designation and this license in any such copy.

https://www.wordfence.com/wordfence-intelligence-terms-and-conditions/