North Grid Proself: xml external entity flaw under attack

What is affected

North Grid Proself 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.

North Grid Proself Enterprise/Standard, Gateway, and Mail Sanitize contain an improper restriction of XML External Entity (XXE) reference vulnerability, which could allow a remote, unauthenticated attacker to conduct an XXE attack.

What an attacker can do

This is a xml external entity flaw. It lets an attacker make the system read local files or contact internal services while it processes a crafted XML document.

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 North Grid Proself 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 mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Vendor advisories and fixes

• proself.jpwww.proself.jp/information/153/

How urgent is it

CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on December 3, 2024, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by December 24, 2024, 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 3.5% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 89% of all scored vulnerabilities.

Its CVSS severity score is 7.5 out of 10 (high), as recorded in the US National Vulnerability Database.

Technical description

Proself Enterprise/Standard Edition Ver5.62 and earlier, Proself Gateway Edition Ver1.65 and earlier, and Proself Mail Sanitize Edition Ver1.08 and earlier allow a remote unauthenticated attacker to conduct XML External Entity (XXE) attacks. By processing a specially crafted request containing malformed XML data, arbitrary files on the server containing account information may be read by the attacker.