ownCloud graphapi: information disclosure flaw under attack

What is affected

ownCloud graphapi 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.

ownCloud graphapi contains an information disclosure vulnerability that can reveal sensitive data stored in phpinfo() via GetPhpInfo.php, including administrative credentials.

What an attacker can do

This is a information disclosure flaw. It lets an attacker read data they are not supposed to see, such as memory contents, credentials or internal files. It is often the first step of a larger attack.

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 ownCloud graphapi 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

• owncloud.comowncloud.com/security-advisories/disclosure-of-sensitive-credentials-and-configuration-in-

How urgent is it

CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on November 30, 2023, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by December 21, 2023, 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 78% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 99.6% 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

An issue was discovered in ownCloud owncloud/graphapi 0.2.x before 0.2.1 and 0.3.x before 0.3.1. The graphapi app relies on a third-party GetPhpInfo.php library that provides a URL. When this URL is accessed, it reveals the configuration details of the PHP environment (phpinfo). This information includes all the environment variables of the webserver. In containerized deployments, these environment variables may include sensitive data such as the ownCloud admin password, mail server credentials, and license key. Simply disabling the graphapi app does not eliminate the vulnerability. Additionally, phpinfo exposes various other potentially sensitive configuration details that could be exploited by an attacker to gather information about the system. Therefore, even if ownCloud is not running in a containerized environment, this vulnerability should still be a cause for concern. Note that Docker containers from before February 2023 are not vulnerable to the credential disclosure.