Urgent Action Required to Address Critical ownCloud Vulnerabilities
Three critical vulnerabilities in the ownCloud platform have been identified, one of which is being actively exploited. Urgent action is required to address the vulnerabilities to protect sensitive networks and sensitive data.
The ownCloud platform is used extensively in healthcare for storing, synchronizing, and sharing files and collaborating and consolidating work processes. As such, the platform is a prime target for malicious actors as it allows them to access highly sensitive data. The Clop hacking groups demonstrated how serious vulnerabilities in file sharing platforms can be, having mass exploited vulnerabilities in Fortra’s GoAnywhere MFT and Progress Software’s MOVEit Transfer solution earlier this year.
Security advisories were issued by ownCloud on November 21, 2023, about three vulnerabilities, the most serious of which has a maximum CVSS v3.1 severity score of 10. The remaining two vulnerabilities have been assigned CVSS scores of 9.8 and 9. Evidence of active exploitation of the flaws was identified by the cybersecurity firm Greynoise from November 25, 2023, with the malicious activity originating from 32 unique IP addresses.
- CVE-2023-49103 – A critical vulnerability in versions 0.2.0 – 0.3.0 of the graphapi app that allows disclosure of sensitive credentials and configuration in containerized deployments. The graphapi app relies on a third-party library that provides a URL. When the URL is accessed, it reveals the configuration details of the PHP environment, which includes environment variables for the webserver. In containerized deployments, the disclosed information can include the ownCloud admin password, mail server credentials, and license key. The vulnerability has a CVSS severity score of 10 out of 10.
- CVE-2023-49105 – A critical WebDAV API authentication bypass vulnerability using pre-signed URLs. The vulnerability affects core 10.6.0 – 10.13.0 and can be exploited to access, modify, or delete any file without authentication if the username of the victim is known and the victim has no signing-key configured, which is the default setting. The vulnerability has a CVSS severity score of 9.8 out of 10.
- CVE-2023-49104 – A critical subdomain validation bypass vulnerability in oauth2 < 0.6.1. An attacker can pass in a specially crafted redirect-URL that bypasses the validation code, allowing the attacker to redirect callbacks to a TLD controlled by the attacker. The vulnerability has a CVSS severity score of 9.0 out of 10.
The Health Sector Cybersecurity Coordination Center (HC3) issued a warning on December 5, 2023, urging HPH sector organizations to take immediate action and apply the actions recommended by ownCloud. “The nature of this platform is such that it needs to be integrated into the information infrastructure of a customer organization to function, which provides attackers with a target that can potentially provide access to sensitive information, as well as a staging point for further attacks,” explained HC3.
Get The FREE
HIPAA Compliance Checklist
Immediate Delivery of Checklist Link To Your Email Address
Please Enter Correct Email Address
Your Privacy Respected
HIPAA Journal Privacy Policy
At present, only the CVE-2023-49103 is believed to have been actively exploited in attacks in the wild. This vulnerability should therefore be treated with the highest priority; however, the remaining vulnerabilities should also be addressed as soon as possible as exploitation is likely.
ownCloud notes that while the graphapi app can be disabled, that will not fully address the CVE-2023-49103 vulnerability. The owncloud/apps/graphapi/vendor/microsoft/microsoft-graph/tests/GetPhpInfo.php file should also be deleted and the phpinfo function should be disabled in Docker containers. Owncloud also recommends changing potentially exposed secrets such as the credentials for ownCloud administration, the mail server, the database, and the Object-Store/S3 access key. Owncloud’s mitigations for the vulnerabilities can be found on the following links:


