Cisco Deals With Serious IOS Vulnerabilities

The flaws affect the IOS FTP Server feature and, if exploited, could give remote attackers the ability to bypass authentication, get their hands on passwords from device file systems or launch malicious code attacks, Cisco said in an advisory.

The more serious of the vulnerabilities has to do with the failure of IOS to properly verify user credentials, which could allow miscreants to gain unauthorized access to devices and boost their privileges, said Cisco, which assigned the maximum CVSS base score of 10 to the flaw.

The second IOS FTP Server bug is triggered when files are being transferred through the device by FTP, which could give attackers a means of launching denial-of-service attacks. Cisco assigned a CVSS base score of 2 to this vulnerability.

IOS versions 11.3, 12.0, 12.1, 12.2, 12.3 and 12.4 include the IOS FTP Server, but the overall impact of the vulnerabilities is mitigated somewhat by the fact that the feature isn't enabled by default, Cisco noted.

San Jose, Calif.-based Cisco has released a fix that disables the IOS FTP server feature, which can also be done by issuing the command "no ftp-server enable" while in configuration mode.

Danish security research firm Secunia rated the vulnerabilities as "moderately critical," or 3 on a 5-point scale, while Symantec Deepsight weighed in with a severity score of 7.9 on its own proprietary rating scale.