Risky Bulletin Newsletter
August 22, 2025
Risky Bulletin: A decade later, Russian hackers are still using SYNful Knock, and it's still working
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News Editor
Cisco and the FBI have asked "the public, private sector, and international community"—also known as "anyone willing to listen"—to patch their stupid end-of-life Cisco routers for an ancient 2018 vulnerability that's being "broadly" exploited by Russian hackers linked to the country's FSB intelligence service.
A group known as Static Tundra has been abusing a bug tracked as CVE-2018-0171 over the past year to install backdoors on old and outdated Cisco routers that are still haunting many corporate and government networks.
Static Tundra has been abusing the vulnerability ever since it was discovered back in 2018, but they expanded operations in 2022 and then again last year, as Russia's war in Ukraine has forced the FSB to ramp up intelligence collection capabilities.