Cisco IOS AAA TCL shell command authentication bypass

cisco-aaa-tcl-auth-bypass (24308) The risk level is classified as MediumMedium Risk

Description:

A vulnerability in the Authentication, Authorization, and Accounting (AAA) feature in multiple Cisco devices running Cisco Internetwork Operating System Software (IOS) could allow a local attacker to bypass command authorization. If Tool Command Language (Tcl) is enabled, an authenticated attacker could exploit this vulnerability to execute arbitrary IOS EXEC commands on the affected device.

Platforms Affected:

  • Cisco, IOS 12.0T
  • Cisco, IOS 12.0XH
  • Cisco, IOS 12.0XK
  • Cisco, IOS 12.0XL
  • Cisco, IOS 12.0XN
  • Cisco, IOS 12.0XR
  • Cisco, IOS 12.1
  • Cisco, IOS 12.1AA
  • Cisco, IOS 12.1E
  • Cisco, IOS 12.1EC
  • Cisco, IOS 12.1EZ
  • Cisco, IOS 12.1GA
  • Cisco, IOS 12.1GB
  • Cisco, IOS 12.1T
  • Cisco, IOS 12.1XA
  • Cisco, IOS 12.1XE
  • Cisco, IOS 12.1XI
  • Cisco, IOS 12.1XJ
  • Cisco, IOS 12.1XL
  • Cisco, IOS 12.1XM
  • Cisco, IOS 12.1XP
  • Cisco, IOS 12.1XQ
  • Cisco, IOS 12.1XS
  • Cisco, IOS 12.1XT
  • Cisco, IOS 12.1XU
  • Cisco, IOS 12.1XV
  • Cisco, IOS 12.1XW
  • Cisco, IOS 12.1XZ
  • Cisco, IOS 12.1YA
  • Cisco, IOS 12.1YB
  • Cisco, IOS 12.1YD
  • Cisco, IOS 12.1YE
  • Cisco, IOS 12.1YF
  • Cisco, IOS 12.1YH
  • Cisco, IOS 12.1YI
  • Cisco, IOS 12.2
  • Cisco, IOS 12.2B
  • Cisco, IOS 12.2BW
  • Cisco, IOS 12.2BY
  • Cisco, IOS 12.2DD
  • Cisco, IOS 12.2DX
  • Cisco, IOS 12.2MX
  • Cisco, IOS 12.2S
  • Cisco, IOS 12.2SU
  • Cisco, IOS 12.2SW
  • Cisco, IOS 12.2SXB
  • Cisco, IOS 12.2SXD
  • Cisco, IOS 12.2SXE
  • Cisco, IOS 12.2SZ
  • Cisco, IOS 12.2XA
  • Cisco, IOS 12.2XB
  • Cisco, IOS 12.2XC
  • Cisco, IOS 12.2XD
  • Cisco, IOS 12.2XG
  • Cisco, IOS 12.2XH
  • Cisco, IOS 12.2XJ
  • Cisco, IOS 12.2XK
  • Cisco, IOS 12.2XL
  • Cisco, IOS 12.2XM
  • Cisco, IOS 12.2XN
  • Cisco, IOS 12.2XQ
  • Cisco, IOS 12.2XS
  • Cisco, IOS 12.2XU
  • Cisco, IOS 12.2XV
  • Cisco, IOS 12.2XW
  • Cisco, IOS 12.2YB
  • Cisco, IOS 12.2YC
  • Cisco, IOS 12.2YD
  • Cisco, IOS 12.2YE
  • Cisco, IOS 12.2YH
  • Cisco, IOS 12.2YK
  • Cisco, IOS 12.2YL
  • Cisco, IOS 12.2YM
  • Cisco, IOS 12.2YN
  • Cisco, IOS 12.2YT
  • Cisco, IOS 12.2YU
  • Cisco, IOS 12.2YW
  • Cisco, IOS 12.2YX
  • Cisco, IOS 12.2YY
  • Cisco, IOS 12.2YZ
  • Cisco, IOS 12.2ZB
  • Cisco, IOS 12.2ZC
  • Cisco, IOS 12.2ZD
  • Cisco, IOS 12.2ZE
  • Cisco, IOS 12.2ZF
  • Cisco, IOS 12.2ZH
  • Cisco, IOS 12.2ZJ
  • Cisco, IOS 12.2ZL
  • Cisco, IOS 12.2ZN
  • Cisco, IOS 12.2ZP
  • Cisco, IOS 12.3
  • Cisco, IOS 12.3B
  • Cisco, IOS 12.3T
  • Cisco, IOS 12.3XA
  • Cisco, IOS 12.3XB
  • Cisco, IOS 12.3XD
  • Cisco, IOS 12.3XE
  • Cisco, IOS 12.3XF
  • Cisco, IOS 12.3XG
  • Cisco, IOS 12.3XH
  • Cisco, IOS 12.3XI
  • Cisco, IOS 12.3XJ
  • Cisco, IOS 12.3XK
  • Cisco, IOS 12.3XM
  • Cisco, IOS 12.3XQ
  • Cisco, IOS 12.3XR
  • Cisco, IOS 12.3XW
  • Cisco, IOS 12.3XY
  • Cisco, IOS 12.3YA
  • Cisco, IOS 12.3YE
  • Cisco, IOS 12.3YF
  • Cisco, IOS 12.3YG
  • Cisco, IOS 12.3YH
  • Cisco, IOS 12.3YI
  • Cisco, IOS 12.3YJ
  • Cisco, IOS 12.3YK
  • Cisco, IOS 12.3YM
  • Cisco, IOS 12.3YQ
  • Cisco, IOS 12.3YS
  • Cisco, IOS 12.3YT
  • Cisco, IOS 12.3YU
  • Cisco, IOS 12.3YX
  • Cisco, IOS 12.4MR
  • Cisco, IOS 12.4T

Remedy:

Refer to cisco-sr-20060125-aaatcl for upgrade or workaround information. See References.

Consequences:

Bypass Security

References:

  • cisco-sr-20060125-aaatcl, Cisco Security Response: AAA Command Authorization by-pass at http://www.cisco.com/warp/public/707/cisco-sr-20060125-aaatcl.shtml.
  • BID-16383: Cisco IOS TCLSH AAA Command Authorization Bypass Vulnerability
  • CVE-1999-0293: AAA authentication on Cisco systems allows attackers to execute commands without authorization.
  • CVE-2006-0485: The TCL shell in Cisco IOS 12.2(14)S before 12.2(14)S16, 12.2(18)S before 12.2(18)S11, and certain other releases before 25 January 2006 does not perform Authentication, Authorization, and Accounting (AAA) command authorization checks, which may allow local users to execute IOS EXEC commands that were prohibited via the AAA configuration, aka Bug ID CSCeh73049.
  • OSVDB ID: 34892: Cisco IOS AAA tclsh Command Authentication Bypass
  • SA18613: Cisco IOS AAA Command Authentication Bypass Vulnerability
  • SECTRACK ID: 1015543: Cisco IOS AAA Command Authorization Feature May Let Remote Authenticated Users Gain Elevated Privileges
  • VUPEN/ADV-2006-0337: Cisco IOS TCLSH AAA Command Authorization Bypass Vulnerability

Reported:

Jan 25, 2006

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