Quantum Secular Labs / Blog / Advisories

CVE-2017-5219: Sagecrm: Improper Limitation of a Pathname to a Restricted Directory

CVE-2017-5219 is rated critical with a CVSS v3.0 base score of 9.8 and affects Sagecrm. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

An issue was discovered in SageCRM 7.x before 7.3 SP3. The Component Manager functionality, provided by SageCRM, permits additional components to be added to the application to enhance provided functionality. This functionality allows a zip file to be uploaded, containing a valid .ecf component file, which will be extracted to the inf directory outside of the webroot. By creating a zip file containing an empty .ecf file, to pass file-validation checks, any other file provided in zip file will be extracted onto the filesystem. In this case, a web shell with the filename '..\WWWRoot\CustomPages\aspshell.asp' was included within the zip file that, when extracted, traversed back out of the inf directory and into the SageCRM webroot. This permitted remote interaction with the underlying filesystem with the highest privilege level, SYSTEM.

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-22: Improper Limitation of a Pathname to a Restricted Directory

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

Affected products

  • Sagecrm: 7.3; 7.3 sp1; 7.3 sp2

References