Lucian Constantin
CSO Senior Writer

Cisco fixes serious denial-of-service flaws in wireless LAN controllers, other products

news
Apr 21, 20162 mins

One of the vulnerabilities is critical and the rest are rated as high severity

Cisco Systems has released patches to fix serious denial-of-service flaws in its Wireless LAN Controller (WLC) software, Cisco Adaptive Security Appliance (ASA) software and the Secure Real-Time Transport Protocol (SRTP) library that’s used in many products.

The Cisco WLC software contains two denial-of-service vulnerabilities, one of which is rated critical and could be exploited by an unauthenticated attacker through specially crafted HTTP requests sent to the device. This can cause a buffer overflow condition that, in addition to a device reload, might also allow for execution of arbitrary code on the device.

The second vulnerability, rated high, stems from how the Cisco WLC software handles Bonjour traffic and can be exploited in a similar manner as the HTTP one to cause a device reload.

A third DoS vulnerability was patched in the Cisco AireOS software that also runs on some of the company’s Wireless LAN Controller devices. It can be exploited by an unauthenticated hacker by attempting to access a URL that is not generally accessible from and supported by the device’s management interface.

The software, used in the Cisco ASA 5500-X Series Next-Generation Firewalls, Cisco ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers and the Cisco Adaptive Security Virtual Appliance (ASAv), has a flaw stemming from an insufficient validation of DHCPv6 packets.

The vulnerability only affects the Cisco ASA Software if it’s configured with the DHCPv6 relay feature and can only be triggered by IPv6 traffic, Cisco said in an advisory.

Finally, a DoS vulnerability in libSRTP that could be exploited through specially crafted SRTP packets, was fixed through software updates for multiple products that use the library for some features. The list of affected products is long but includes Cisco WebEx Meetings Server, Cisco Jabber, Cisco Adaptive Security Appliance (ASA) Software, Cisco IOS XE Software and many Cisco voice and unified communications devices.

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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