Cybersecurity firm Genua has issued a fix for a risky flaw in in it’s two-tier firewall product, GenuGate High Resistance Firewall. The vulnerability could have enabled attackers to bypass authentication measures and log in as root users within a company’s internal network.
“An unauthenticated attacker is able to login as an arbitrary user in the admin web interface successfully, the side channel interface and user web interface, even as root with highest privileges, by manipulating certain HTTP POST parameters during login,” according to security and application consultation company SEC Consult on Monday.
What does the GenuGate High Resistance Firewall do?
According to Genua, the firewall protects internal networks from unauthorized access and lets organizations create an intranet with various domains, each with it’s own protection measures.
Has the flaw been fixed in all versions of the firewall?
Versions below 10.1p4, 9.6p7 and versions 9.0, and those below Zp19 are vulnerable.
The flaw has been fixed in GenuGate versions 10.1 p4 (G1010_004); 9.6 p7 (G960_007); 9.0 and 9.0 Z p19 (G900_019).
What do experts have to say?
“The vendor provides a patched version for the affected products which should be installed immediately,” says SEC Consult, a security and application consultancy company. “Customers should also adhere to security best practices such as network segmentation and limiting access to the admin panel. This is also a requirement for certified and approved environments.”
The flaw
The firewall has different authentication methods for the admin web interface, sidechannel web and user web interface. These many authentication methods make the authentication bypass vulnerability (CVE-2021027215) dangerous.
Due to the flaw, certain HTTP POST parameters passed to the server go unchecked, and hence any authentication request is allowed.
Rigging a specific parameter method would enable an attacker to bypass authentication and login as an arbitrary user. They could even login as non-existing user, said SEC Consult researchers.
SEC researchers even released a high-level proof-of-concept exploit of the bug, including a video. However, given the critical nature of the flaw, they did not release any specific POC details that might help the attackers themselves.
The only silver lining was, to exploit the flaw an attacker would’ve needed network access to the admin interface.
“Certified and approved environments mandate that the admin interface is only reachable through a strictly separated network,” according to SEC Consult. “Nevertheless, it is a highly critical security vulnerability and must be patched immediately.”
Quick response by Genua saves the day Genua was notified about the vulnerability by researchers on Jan 29. The company confirmed the issue the same day and rolled out the fix on Feb 2. The public disclosure of the vulnerability (in coordination with CERT-Bund and CERT) was published on Monday. SEC Consult said, the patch can be downloaded in GenuGate GUI or by calling “getpatches” on the command line interface.
