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CVE-2016-7095: Exponent CMS: Unrestricted Upload of File with Dangerous Type

CVE-2016-7095 is rated critical with a CVSS v3.0 base score of 9.8 and affects Exponent CMS. 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

Exponent CMS before 2.3.9 is vulnerable to an attacker uploading a malicious script file using redirection to place the script in an unprotected folder, one allowing script execution.

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-434: Unrestricted Upload of File with Dangerous Type

The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.

Affected products

• Exponent CMS: up to and including 2.3.8

References

• http://www.exponentcms.org/news/security-vulnerability-all-exponent-versions-june-2016
• http://www.securityfocus.com/bid/94121
• https://github.com/exponentcms/exponent-cms/releases/tag/v2.4.0