Quantum Secular Labs / Blog / Advisories
CVE-2018-3985: Getcujo Smart Firewall: Authentication bypass
CVE-2018-3985 is rated critical with a CVSS v3.1 base score of 9.8 and affects Getcujo Smart Firewall. 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 exploitable double free vulnerability exists in the mdnscap binary of the CUJO Smart Firewall. When parsing mDNS packets, a memory space is freed twice if an invalid query name is encountered, leading to arbitrary code execution in the context of the mdnscap process. An unauthenticated attacker can send an mDNS message to trigger this vulnerability.
Severity breakdown
CVSS v3.1 9.8: CVSS:3.1/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-415: Double Free
The product calls free() twice on the same memory address.
Affected products
- Getcujo Smart Firewall: 7003