WordPress Social Warfare Plugin: cross-site scripting flaw under attack

What is affected

WordPress Social Warfare Plugin is mostly run by companies, schools and public bodies, not on home computers. You are unlikely to have it yourself, but organisations that hold your data may. Breaches that start with flaws like this one are how personal data ends up leaked.

WordPress Social Warfare plugin contains a cross-site scripting (XSS) vulnerability that allows for remote code execution. This vulnerability affects Social Warfare and Social Warfare Pro.

What an attacker can do

This is a cross-site scripting flaw. It lets an attacker plant a script that runs in the browser of anyone who opens the affected page, which lets them steal that person's session or act on their behalf.

How it is reached

Over the internet or network

Access the attacker needs

No account needed

Does the victim have to do something?

Yes, the victim must open or click something

What to do

1. At home: nothing to install. Keep your own devices updated and use a different password for every service, so that a breach at one organisation does not open your other accounts.
2. If you administer WordPress Social Warfare Plugin at work: apply the vendor's fix or mitigation now and review logs for signs of compromise, because the flaw was being exploited before it was listed.
3. If the product is past its support date and no fix exists, take it off the internet or retire it.

Apply updates per vendor instructions.

How urgent is it

CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on November 3, 2021, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by May 3, 2022, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.

The EPSS model estimates a 73% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 99.4% of all scored vulnerabilities.

Its CVSS severity score is 6.1 out of 10 (medium), as recorded in the US National Vulnerability Database.

Technical description

The social-warfare plugin before 3.5.3 for WordPress has stored XSS via the wp-admin/admin-post.php?swp_debug=load_options swp_url parameter, as exploited in the wild in March 2019. This affects Social Warfare and Social Warfare Pro.