phpBB gen_rand_string() weak random number generator

phpbb-weak-rnd (24573)

Low Risk

Description:

phpBB use the gen_rand_string() function to generate predictable random numbers. A remote attacker with knowledge of a phpBB user's username and email address could exploit this weakness in combination with the "I forgot my password" option to determine a user's password using brute force techniques.

*CVSS:

Base Score:	2.8
Access Vector:	Remote
Access Complexity:	High
Authentication:	Not Required
Confidentiality Impact:	Partial
Integrity Impact:	None
Availability Impact:	None
Temporal Score:	2.1
Exploitability:	Unproven
Remediation Level:	Official-Fix
Report Confidence:	Confirmed

Consequences:

Other

Remedy:

Upgrade to the latest version of phpBB (2.0.19 or later), available from the phpBB Web site. See References.

References:

• phpBB Web site: phpBB:: Creating Communities.
• r-security dot net: Exploiting PRNGs in PHP.

Platforms Affected:

• phpBB phpBB 2.0.19

Reported:

Feb 05, 2006

The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the author/distributor (IBM Internet Security Systems X-Force) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

For corrections or additions please email xforce@iss.net

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The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall IBM be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

About IBM Internet Security Systems

IBM Internet Security Systems is a trusted security advisor to thousands of the world's leading businesses and governments, helping to provide pre-emptive protection for networks, desktops and servers. The IBM Proventia? integrated security platform is designed to automatically protect against both known and unknown threats, helping to keep networks up and running and shield customers from online attacks before they impact business assets. IBM Internet Security Systems products and services are based on the proactive security intelligence of its X-Force? research and development team ? an unequivocal world authority in vulnerability and threat research. The IBM Internet Security Systems product line is also complemented by comprehensive Managed Security Services and Professional Security Services. For more information, visit the IBM Internet Security Systems Web site at www.iss.net or call 800-776-2362.