Businesses are being warned that three Cisco Systems router operating-system vulnerabilities have been discovered.
The flaws found could enable a malicious individual to commit denial-of-service, or DoS, attacks against Web sites, according to a warning issued by the U.S. Computer Emergency Readiness Team.
US-CERT's warning about the Cisco IOS issue says a remote attacker would be able to execute code on affected devices.
Users are being told to upgrade to a fixed version of IOS, which stands for Internetwork Operating System.
"Cisco is aware of multiple vulnerabilities that may impact Cisco IOS and IOS XR devices, and has published three separate security advisories about them," the network hardware maker said in a statement.
"In all cases, Cisco has made free software available to address the vulnerabilities for affected customers," the company said. "Cisco is also not aware of any current exploitation of these vulnerabilities."
Will Sturgeon of Silicon.com reported from London.