SB2019072904 - Privilege escalation in ownCloud

Description

This security bulletin contains information about 2 vulnerabilities.

1) Improper privilege management (CVE-ID: N/A)

CWE-ID: CWE-269 - Improper Privilege Management

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to gain elevated privileges.

The vulnerability exists due to the possibility to extend internal-share permissions using the API. A remote attacker can extend the permission of a received subfolder share using the ocs api and gain elevated privileges. Additional risk exists because the privileged extension is also possible on public-shares.

2) Improper Privilege Management (CVE-ID: N/A)

CWE-ID: CWE-269 - Improper Privilege Management

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to gain elevated privileges.

The vulnerability exists due to the possibility to extend internal-share permissions using the API. A remote authenticated attacker can extend the permission of a received internal-share using the ocs-api and gain elevated privileges.

Remediation

Install update from vendor's website.

References

• https://owncloud.org/security/advisories/possibility-to-extend-internal-share-permissions-using-the-api/
• https://github.com/owncloud/core/commit/c93eca49c32428ece03dd67042772d5fa62c8d6e
• https://owncloud.org/security/advisories/possibility-to-extend-internal-share-permissions-using-the-api2/
• https://github.com/owncloud/core/commit/4ae39f7c70bb26e55d7396184da5c30dd75980a3