Lucian Constantin
CSO Senior Writer

Flaws expose Cisco RV series routers, firewalls to hacking

news
Jun 17, 20162 mins

Attackers can take control of the affected devices by sending specifically crafted HTTP requests to them

Three models of Cisco wireless VPN firewalls and routers from the small business RV series contain a critical unpatched vulnerability that attackers can exploit remotely to take control of devices.

The vulnerability is located in the web-based management interface of the Cisco RV110W Wireless-N VPN Firewall, RV130W Wireless-N Multifunction VPN Router and RV215W Wireless-N VPN Router.

It can be easily exploited if the affected devices are configured for remote management since attackers only need to send an unauthenticated HTTP request with custom user data. This will result in remote code execution as root, the highest privileged account on the system, and can lead to a complete compromise.

Cisco Systems warned about the vulnerability in a security advisory this week, but no patches are yet available. The company plans to release firmware updates that will address this flaw on affected models sometime in the third quarter of 2016.

Worse yet, this is not the only unpatched vulnerability that exists in these three Cisco devices. The company also warned of a medium-severity, cross-site scripting (XSS) flaw and two medium-risk buffer overflows that could result in denial-of-service conditions.

While exploiting the buffer overflows requires attackers to have an authenticated session in the device’s web-based interface, the XSS flaw can be triggered by tricking authenticated users to click on specifically crafted URLs.

“A successful exploit could allow the attacker to execute arbitrary script in the context of the web-based management interface for the device or allow the attacker to access sensitive browser-based information,” Cisco said in an advisory.

The XSS flaw makes it difficult for users to find a mitigation strategy in the absence of patches, because it can be combined with the other vulnerabilities. For example, if users disable external management in their devices in order to protect them from the critical vulnerability, the devices will still be exposed through the cross-site scripting flaw.

Lucian Constantin

Lucian Constantin writes about information security, privacy, and data protection for CSO. Before joining CSO in 2019, Lucian was a freelance writer for VICE Motherboard, Security Boulevard, Forbes, and The New Stack. Earlier in his career, he was an information security correspondent for the IDG News Service and Information security news editor for Softpedia.

Before he became a journalist, Lucian worked as a system and network administrator. He enjoys attending security conferences and delving into interesting research papers. He lives and works in Romania.

You can reach him at lucian_constantin@foundryco.com or @lconstantin on X. For encrypted email, his PGP key's fingerprint is: 7A66 4901 5CDA 844E 8C6D 04D5 2BB4 6332 FC52 6D42

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