October CMS: authentication bypass flaw under attack

What is affected

October CMS 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.

In affected versions of the october/system package an attacker can request an account password reset and then gain access to the account using a specially crafted request.

What an attacker can do

This is a authentication bypass flaw. It lets an attacker get in without a valid username and password and act as a legitimate user, often as an administrator.

How it is reached

Over the internet or network

Access the attacker needs

No account needed

Does the victim have to do something?

No, works without the victim doing anything

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 October CMS 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 January 18, 2022, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by February 1, 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 90% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 99.8% of all scored vulnerabilities.

Its CVSS severity score is 9.1 out of 10 (critical), as recorded in the US National Vulnerability Database.

Technical description

octobercms in a CMS platform based on the Laravel PHP Framework. In affected versions of the october/system package an attacker can request an account password reset and then gain access to the account using a specially crafted request. The issue has been patched in Build 472 and v1.1.5.