CyberSecBulletin
CVE-2024-8981NVD status: Deferred

Broken Link Checker: Improper Neutralization of Script-Related HTML Tags in a Web Page

Published Updated By the CyberSecBulletin desk

CVE-2024-8981 is a high-severity improper neutralization of script-related HTML tags in a web page vulnerability in Broken Link Checker from Wpmudev, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected Broken Link Checker versions: 2.4.0 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.5% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Broken Link Checker you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
WpmudevBroken Link Checker2.4.0 and earlierNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
LowSome restricted data can be read.
Integrity
LowLimited modification of data is possible.
Availability
LowPerformance or availability is reduced.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L. Scored by CNA (wordfence.com).

Official description

The Broken Link Checker plugin for WordPress is vulnerable to Reflected Cross-Site Scripting due to the use of add_query_arg in /app/admin-notices/features/class-view.php without appropriate escaping on the URL in all versions up to, and including, 2.4.0. 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Neutralization of Script-Related HTML Tags in a Web Page

The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as <, >, and & that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.

How developers prevent this class of flaw

  • With Struts, write all data from form beans with the bean's filter attribute set to true.

More Improper Neutralization of Script-Related HTML Tags in a Web Page vulnerabilities (CWE-80)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Broken Link Checker

All Broken Link Checker vulnerabilities

Recent Improper Neutralization of Script-Related HTML Tags in a Web Page vulnerabilities

Spotted an error? Tell us.