Cisco Warns About Product Flaws for iOS and IOS XE Systems

Cisco reports that anyone using their software products designed for iOS or IOS XE should be aware of a few issues. During some testing, nine flaws were discovered and several of them are listed as high severity. They affect all versions of the Simple Network Management Protocol (SNMP) component of iOS and IOS XE and while normally they should be patched right away, fixes for these are not yet available.

What can happen is that an attacker can take advantage of this and execute code remotely or cause the device to reload, if they know the SNMP read-only community string of the system they are targeting. That means, they must know the password to change these permissions. So, while it is difficult to exploit these, it is not impossible.

Since patches have not yet been released, there are some workarounds and additional information on how to react to these available from Cisco's website.

If any devices are configured with the following MIBs, they are vulnerable. These are also the ones enabled by default.

    •    ADSL-LINE-MIB

    •    ALPS-MIB

    •    CISCO-ADSL-DMT-LINE-MIB

    •    CISCO-BSTUN-MIB

    •    CISCO-MAC-AUTH-BYPASS-MIB

    •    CISCO-SLB-EXT-MIB

    •    CISCO-VOICE-DNIS-MIB

    •    CISCO-VOICE-NUMBER-EXPANSION-MIB

    •    TN3270E-RT-MIB

In other news from Cisco, patches were released for some Prime Infrastructure issues from last November. These were high and medium severity found by a separate company and reported to Cisco. They include SQL injection, XML external entity (XXE), cross-site scripting (XSS), and local file disclosure weaknesses. They are also remote code execution flaws. More information and patches for these can be found at Cisco's Security Advisories and Alerts page.