CVE-2021-24635

Visual Link Preview <= 2.2.2 - Unauthorised AJAX Calls

2021-08-18 00:00

Strategic Overview

Status: Patched in 2.2.3
Affected Plugin: Visual Link Preview
Affected Version: < 2.2.3
CVSS: 5.4Medium
Weakness type: CWE-284 · Improper Access Control
CVE: CVE-2021-24635

View all Visual Link Preview vulnerabilities

At a glance

CVE-2021-24635 is a medium-severity Improper Access Control vulnerability in the Visual Link Preview WordPress plugin, affecting versions < 2.2.3. It carries a CVSS score of 5.4 (reachable over the network; low attack complexity). The issue is fixed in version 2.2.3; sites on affected versions should update now. Disclosed August 2021, reported by apple502j.

Vulnerability Overview

The Visual Link Preview WordPress plugin before 2.2.3 does not enforce authorisation on several AJAX actions and has the CSRF nonce displayed for all authenticated users, allowing any authenticated user (such as subscriber) to call them and 1) Get and search through title and content of Draft post, 2) Get title of a password-protected post as well as 3) Upload an image from an URL

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.

CWE-284: Improper Access Control

Reaching this weakness in Visual Link Preview < 2.2.3 takes a caller who can reach the endpoint. Improper access control means the code decides what a caller may do using something other than their actual permissions, so the decision can be wrong without any check appearing to be missing.

Whoever can shape the request decides the answer, so the protected action runs for callers the code never meant to allow. For Visual Link Preview the fix is 2.2.3: builds < 2.2.3 are affected, anything from 2.2.3 onward is not.

Remediation

Update to version 2.2.3, or a newer patched version

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: Visual Link Preview 2.2.3 closes this, and updating the plugin is the step that ends it.

Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24635 https://www.wordfence.com/threat-intel/vulnerabilities/id/012e019f-9146-45bc-b4d7-aa724dbebdc6 https://nvd.nist.gov/vuln/detail/CVE-2021-24635

Related records

CVSS Vector

5.4

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

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