CVE-2016-6473: A vulnerability in Cisco IOS on Catalyst Switches and Nexus 9300 Series Switches could allow an unauthenticated, adjacent attacker to cause a Layer 2 network st

A vulnerability in Cisco IOS on Catalyst Switches and Nexus 9300 Series Switches could allow an unauthenticated, adjacent attacker to cause a Layer 2 network st

A vulnerability in Cisco IOS on Catalyst Switches and Nexus 9300 Series Switches could allow an unauthenticated, adjacent attacker to cause a Layer 2 network storm. More Information: CSCuu69332, CSCux07028. Known Affected Releases: 15.2(3)E. Known Fixed Releases: 12.2(50)SE4 12.2(50)SE5 12.2(50)SQ5 12.2(50)SQ6 12.2(50)SQ7 12.2(52)EY4 12.2(52)SE1 12.2(53)EX 12.2(53)SE 12.2(53)SE1 12.2(53)SE2 12.2(53)SG10 12.2(53)SG11 12.2(53)SG2 12.2(53)SG9 12.2(54)SG1 12.2(55)EX3 12.2(55)SE 12.2(55)SE1 12.2(55)SE10 12.2(55)SE2 12.2(55)SE3 12.2(55)SE4 12.2(55)SE5 12.2(55)SE6 12.2(55)SE7 12.2(55)SE8 12.2(55)SE9 12.2(58)EZ 12.2(58)SE1 12.2(58)SE2 12.2(60)EZ 12.2(60)EZ1 12.2(60)EZ2 12.2(60)EZ3 12.2(60)EZ4 12.2(60)EZ5 12.2(60)EZ6 12.2(60)EZ7 12.2(60)EZ8 15.0(1)EY2 15.0(1)SE 15.0(1)SE2 15.0(1)SE3 15.0(2)EA 15.0(2)EB 15.0(2)EC 15.0(2)ED 15.0(2)EH 15.0(2)EJ 15.0(2)EJ1 15.0(2)EK1 15.0(2)EX 15.0(2)EX1 15.0(2)EX3 15.0(2)EX4 15.0(2)EX5 15.0(2)EY 15.0(2)EY1 15.0(2)EY2 15.0(2)EZ 15.0(2)SE 15.0(2)SE1 15.0(2)SE2 15.0(2)SE3 15.0(2)SE4 15.0(2)SE5 15.0(2)SE6 15.0(2)SE7 15.0(2)SE9 15.0(2)SG10 15.0(2)SG3 15.0(2)SG6 15.0(2)SG7 15.0(2)SG8 15.0(2)SG9 15.0(2a)EX5 15.1(2)SG 15.1(2)SG1 15.1(2)SG2 15.1(2)SG3 15.1(2)SG4 15.1(2

Description from the National Vulnerability Database, published by psirt@cisco.com

What it means for a small business

IOS is network equipment or remote-access software: the box between your office and the internet. These are a favorite target because breaking one opens the whole office.

If an IT provider set it up, ask them to confirm the firmware version and the date it was updated. If nobody looks after it, that's the bigger problem.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.64%, higher than 50% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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