UltraVNC Weak Challenge-Response Authentication Vulnerability

BID:17824

Info

UltraVNC Weak Challenge-Response Authentication Vulnerability

Bugtraq ID: 17824
Class: Design Error
CVE:
Remote: Yes
Local: No
Published: May 03 2006 12:00AM
Updated: Jun 21 2006 09:45PM
Credit: Deon Force discovered this vulnerability.
Vulnerable: Ultr@VNC Ultr@VNC 1.0.1
Not Vulnerable: Ultr@VNC Ultr@VNC 1.0.2

Discussion

UltraVNC Weak Challenge-Response Authentication Vulnerability

UltraVNC is susceptible to a weak challenge-response authentication vulnerability. This issue is due to the use of insecure encryption during the authentication process of UltraVNC.

Exploiting this issue allows attackers to gain access to the plaintext password used during the UltraVNC authentication process. This will aid them in further attacks.

UltraVNC version 1.0.1 is vulnerable to this issue; other versions may also be affected.

Exploit / POC

UltraVNC Weak Challenge-Response Authentication Vulnerability

Attackers use standard network-capture software and decryption utilities to exploit this issue.

An updated VNCrackX4 application may be available at the referenced 'www.phenoelit.de' URI; this application can obtain plaintext passwords from captured challenge-response data.

Solution / Fix

UltraVNC Weak Challenge-Response Authentication Vulnerability

Solution:
The vendor has released version 1.0.2 to address this issue. Users are advised to contact the vendor for details on obtaining the appropriate updates.

References

UltraVNC Weak Challenge-Response Authentication Vulnerability

References:
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