SID 3664

Msg

"EXPLOIT PPTP echo request buffer overflow attempt"

Summary

The Point to Point Tunneling Protocol (PPTP) is used to connect client machines to internal corporate resources using a Virtual Private Network

(VPN) across a public network such as the Internet via an encrypted session. Specifically an attempt to overflow a fixed length buffer in the PoPToP daemon.

Classtype

attempted-admin

Impact

Serious. Execution of code with root privileges may be possible.

Detailed Information

A vulnerability in the PoPToP daemon may allow an attacker to overflow a fixed length buffer when processing user supplied data.

Specifically, the user supplied "length" variable is not properly checked before being used in a calculation to determine the amount of data to be received. It is possible to manipulate the variable so that it returns a negative value. This value can then be used to overwrite portions of system memory with code of the attackers choosing.

Affected Systems

  • PoPToP Server 1.1.3 and prior
  • PoPToP Server 1.1.4-b2 and prior

Attack Scenarios

Exploits are publicly available.

Ease Of Attack

Simple

False Positives

None Known

False Negatives

None Known

Contributors

  • Sourcefire Vulnerability Research Team
  • Alex Kirk
  • Nigel Houghton