## Description

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.

## Severity

Overall Severity: N/A

### CVSS Metrics

Type | Score | Severity | Vector
--- | --- | --- | ---

## Affected Products

### cisco - ios

Affected Versions:

- 11.3aa

### cisco - ios

Affected Versions:

- 12.0\(2\)

### cisco - ios

Affected Versions:

- 12.0\(2\)xc

### cisco - ios

Affected Versions:

- 12.0\(2\)xd

### cisco - ios

Affected Versions:

- 12.0\(2\)xf

### cisco - ios

Affected Versions:

- 12.0\(2\)xg

### cisco - ios

Affected Versions:

- 12.0\(3\)t2

### cisco - ios

Affected Versions:

- 12.0\(4\)

### cisco - ios

Affected Versions:

- 12.0\(4\)s

### cisco - ios

Affected Versions:

- 12.0\(4\)t

### cisco - ios

Affected Versions:

- 12.0\(5\)

### cisco - ios

Affected Versions:

- 12.0\(6\)

### cisco - ios

Affected Versions:

- 12.0\(7\)t

### cisco - accesspath

Affected Versions:

- ls-3

### cisco - accesspath

Affected Versions:

- ts-3

### cisco - accesspath

Affected Versions:

- vs-3

### cisco - as5200

Affected Versions:

- *

### cisco - as5300

Affected Versions:

- *

### cisco - as5800

Affected Versions:

- *

### cisco - system_controller_3640

Affected Versions:

- *

### cisco - voice_gateway_as5800

Affected Versions:

- *

### cisco - 3660_router

Affected Versions:

- *

### cisco - 7100_router

Affected Versions:

- *

### cisco - 7200_router

Affected Versions:

- *

### cisco - 7500_router

Affected Versions:

- *

### cisco - ubr7200

Affected Versions:

- *

## References

- http://www.cisco.com/warp/public/707/iostelnetopt-pub.shtml
  Patch Vendor Advisory
- http://www.osvdb.org/1289
- http://www.securityfocus.com/bid/1123
- http://www.cisco.com/warp/public/707/iostelnetopt-pub.shtml
  Patch Vendor Advisory
- http://www.osvdb.org/1289
- http://www.securityfocus.com/bid/1123

Neural Processor Active