Cisco IOS 11.x and 12.x allows remote attackers to cause a denial of service by sending the ENVIRON option to the Telnet daemon before it is ready to accept it, which causes the system to reboot.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ios | Cisco | 11.3aa (including) | 11.3aa (including) |
| Ios | Cisco | 12.0(2) (including) | 12.0(2) (including) |
| Ios | Cisco | 12.0(2)xc (including) | 12.0(2)xc (including) |
| Ios | Cisco | 12.0(2)xd (including) | 12.0(2)xd (including) |
| Ios | Cisco | 12.0(2)xf (including) | 12.0(2)xf (including) |
| Ios | Cisco | 12.0(2)xg (including) | 12.0(2)xg (including) |
| Ios | Cisco | 12.0(3)t2 (including) | 12.0(3)t2 (including) |
| Ios | Cisco | 12.0(4) (including) | 12.0(4) (including) |
| Ios | Cisco | 12.0(4)s (including) | 12.0(4)s (including) |
| Ios | Cisco | 12.0(4)t (including) | 12.0(4)t (including) |
| Ios | Cisco | 12.0(5) (including) | 12.0(5) (including) |
| Ios | Cisco | 12.0(6) (including) | 12.0(6) (including) |
| Ios | Cisco | 12.0(7)t (including) | 12.0(7)t (including) |