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CVE-2017-6900: Riello Ups Netman 204 Firmware: Command injection
CVE-2017-6900 is rated critical with a CVSS v3.0 base score of 9.8 and NVD lists Riello Ups Netman 204 Firmware as the affected product. 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 Riello NetMan 204 14-2 and 15-2. The issue is with the login script and wrongpass Python script used for authentication. When calling wrongpass, the variables $VAL0 and $VAL1 should be enclosed in quotes to prevent the potential for Bash command injection. Further to this, VAL0 and VAL1 should be sanitised to ensure they do not contain malicious characters. Passing it the username of '-' will cause it to time out and log the user in because of poor error handling. This will log the attacker in as an administrator where the telnet / ssh services can be enabled, and the credentials for local users can be reset. Also, login.cgi accepts the username as a GET parameter, so login can be achieved by browsing to the /cgi-bin/login.cgi?username=-%20a URI.
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.
Affected products
- Riello Ups Netman 204 Firmware: 14-2; 15-2