CVE-2019-15713

My Calendar <= 3.1.9 - Unauthenticated Cross-Site Scripting

2019-04-30 00:00

Strategic Overview

Status: Patched in 3.1.10
Affected Plugin: My Calendar – Accessible Event Manager
Affected Version: <= 3.1.9
CVSS: 6.1Medium
Weakness type: CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE: CVE-2019-15713

View all My Calendar – Accessible Event Manager vulnerabilities

At a glance

CVE-2019-15713 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the My Calendar WordPress plugin, affecting versions <= 3.1.9. 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 3.1.10; sites on affected versions should update now. Disclosed April 2019.

Vulnerability Overview

The my-calendar plugin before 3.1.10 for WordPress has XSS.

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')

Reaching this weakness in My Calendar <= 3.1.9 takes no account at all. 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 My Calendar the fix is 3.1.10: builds <= 3.1.9 are affected, anything from 3.1.10 onward is not.

Remediation

Update to version 3.1.10, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: My Calendar 3.1.10 closes this, and updating the plugin is the step that ends it.

Firewall
Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2019-15713 https://www.wordfence.com/threat-intel/vulnerabilities/id/b0d9362f-3f34-4602-b19f-2d283e4fe22d https://nvd.nist.gov/vuln/detail/CVE-2019-15713

Related records

Same weakness class

Other vulnerabilities in My Calendar – Accessible Event Manager

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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